1758:
616:
1944:, ANSI Y14.6 defines standards for indicating threaded parts. Parts are indicated by their nominal diameter (the nominal major diameter of the screw threads), pitch (number of threads per inch), and the class of fit for the thread. For example, â.750-10 UNC-2Aâ is male (A) with a nominal major diameter of 0.750 inches, 10 threads per inch, and a class-2 fit; â.500-20 UNF-1Bâ would be female (B) with a 0.500-inch nominal major diameter, 20 threads per inch, and a class-1 fit. An arrow points from this designation to the surface in question.
1725:
1745:
958:
741:
1920:) was created. With continental Europe and much of the rest of the world turning to SI and ISO metric screw thread, the UK gradually leaned in the same direction. The ISO metric screw thread is now the standard that has been adopted worldwide and is slowly displacing all former standards, including UTS. In the U.S., where UTS is still prevalent, over 40% of products contain at least some ISO metric screw threads. The UK has completely abandoned its commitment to UTS in favour of ISO metric threads, and Canada is in between.
1893:). Therefore, in theory, one might expect that by the start of World War II, the problem of screw thread interchangeability would have already been completely solved. Unfortunately, this proved to be false. Intranational interchangeability was widespread, but international interchangeability was less so. Problems with lack of interchangeability among American, Canadian, and British parts during World War II led to an effort to unify the inch-based standards among these closely allied nations, and the
906:
1901:, with the hope that they would be adopted universally. (The original UTS standard may be found in ASA (now ANSI) publication, Vol. 1, 1949.) UTS consists of Unified Coarse (UNC), Unified Fine (UNF), Unified Extra Fine (UNEF) and Unified Special (UNS). The standard was widely taken up in the UK, although a small number of companies continued to use the UK's own British standards for Whitworth (BSW), British Standard Fine (BSF) and British Association (BA) microscrews.
446:
1331:
833:
825:
248:
256:
1127:, would have a pitch diameter 0.0005 Ă 3 = 0.0015 inch larger than base pitch diameter and would thus result in cutting an internal thread with a looser fit than say an H2 tap. Metric uses D or DU limits which is the same system as imperial, but uses D or DU designators for over and undersized respectively, and goes by units of 0.013 mm (0.51 mils). Generally taps come in the range of H1 to H5 and rarely L1.
31:
949:
which is less than caliper measurement of the male major diameter (outside diameter, OD). For example, tables of caliper measurements show 0.69 female ID and 0.75 male OD for the standards of "3/4 SAE J512" threads and "3/4-14 UNF JIS SAE-J514 ISO 8434-2". Note the female threads are identified by the corresponding male major diameter (3/4 inch), not by the actual measurement of the female threads.
972:) of a particular thread, internal or external, is the diameter of a cylindrical surface, axially concentric to the thread, which intersects the thread flanks at equidistant points. When viewed in a cross-sectional plane containing the axis of the thread, the distance between these points being exactly one half the pitch distance. Equivalently, a line running parallel to the axis and a distance
1809:, proposing a new standard to replace the US' poorly standardized screw thread practice. Sellers simplified the Whitworth design by adopting a thread profile of 60° and a flattened tip (in contrast to Whitworth's 55° angle and rounded tip). The 60° angle was already in common use in America, but Sellers's system promised to make it and all other details of threadform consistent.
1859:, which defined the new international metric thread standards as having the same profile as the Sellers thread, but with metric sizes. Efforts were made in the early 20th century to convince the governments of the U.S., UK, and Canada to adopt these international thread standards and the metric system in general, but they were defeated with arguments that the
38:. The operator rotates the small vertical bevel gear in the center. Through mechanical advantage this causes the horizontal bevel gears (at far left and far right, with threaded center holes) to rotate. Their rotation raises or lowers the two long vertical threaded shafts - as they are not free to rotate.
1812:
The
Sellers thread, easier to produce, became an important standard in the U.S. during the late 1860s and early 1870s, when it was chosen as a standard for work done under U.S. government contracts, and it was also adopted as a standard by highly influential railroad industry corporations such as the
1066:
A general-purpose micrometer (flat anvil and spindle) is used over a set of three wires that rest on the thread flanks, and a known constant is subtracted from the reading. (The wires are truly gauge pins, being ground to precise size, although "wires" is their common name.) This method is called the
1047:
of fit for ranges of thread sizes. At one extreme, no allowance is provided by a class, but the maximum PD of the external thread is specified to be the same as the minimum PD of the internal thread, within specified tolerances, ensuring that the two can be assembled, with some looseness of fit still
89:
is sufficient to prevent linear motion being converted to rotary, that is so the screw does not slip even when linear force is applied, as long as no external rotational force is present. This characteristic is essential to the vast majority of its uses. The tightening of a fastener's screw thread is
724:
Coarse threads are those with larger pitch (fewer threads per axial distance), and fine threads are those with smaller pitch (more threads per axial distance). Coarse threads have a larger threadform relative to screw diameter, where fine threads have a smaller threadform relative to screw diameter.
1982:
Another common inspection point is the straightness of a bolt or screw. This topic comes up often when there are assembly issues with predrilled holes as the first troubleshooting point is to determine if the fastener or the hole is at fault. ASME B18.2.9 "Straightness Gage and Gaging for Bolts and
948:
In order to fit a male thread into the corresponding female thread, the female major and minor diameters must be slightly larger than the male major and minor diameters. However this excess does not usually appear in tables of sizes. Calipers measure the female minor diameter (inside diameter, ID),
884:
The major diameter of threads is the larger of two extreme diameters delimiting the height of the thread profile, as a cross-sectional view is taken in a plane containing the axis of the threads. For a screw, this is its outside diameter (OD). The major diameter of a nut cannot be directly measured
888:
The major diameter of external threads is normally smaller than the major diameter of the internal threads, if the threads are designed to fit together. But this requirement alone does not guarantee that a bolt and a nut of the same pitch would fit together: the same requirement must separately be
815:
Coarse threads are more resistant to stripping and cross threading because they have greater flank engagement. Coarse threads install much faster as they require fewer turns per unit length. Finer threads are stronger as they have a larger stress area for the same diameter thread. Fine threads are
1873:
During the late 19th and early 20th centuries, engineers found that ensuring the reliable interchangeability of screw threads was a multi-faceted and challenging task that was not as simple as just standardizing the major diameter and pitch for a certain thread. It was during this era that more
1027:
Provided that there are moderate non-negative clearances between the root and crest of the opposing threads, and everything else is ideal, if the pitch diameters of a screw and nut are exactly matched, there should be no play at all between the two as assembled, even in the presence of positive
940:
As shown in the figure at right, threads of equal pitch and angle that have matching minor diameters, with differing major and pitch diameters, may appear to fit snugly, but only do so radially; threads that have only major diameters matching (not shown) could also be visualized as not allowing
1752:
of 1916. Standards seen here overlap with those found elsewhere marked as ASME and SAE standards and with the later
Unified Thread Standard (UTS) of 1949 and afterward. One can see the theme of how later standards reflect a degree of continuation from earlier standards, sometimes with hints of
1351:
of screw threads has evolved since the early nineteenth century to facilitate compatibility between different manufacturers and users. The standardization process is still ongoing; in particular there are still (otherwise identical) competing metric and inch-sized thread standards widely used.
668:
threadforms, their lead and pitch are the same. Single-start means that there is only one "ridge" wrapped around the cylinder of the screw's body. Each time that the screw's body rotates one turn (360°), it has advanced axially by the width of one ridge. "Double-start" means that there are two
1931:
Even today, over a half century since the UTS superseded the USS and SAE series, companies still sell hardware with designations such as "USS" and "SAE" to convey that it is of inch sizes as opposed to metric. Most of this hardware is in fact made to the UTS, but the labeling and cataloging
932:
The minor diameter is the lower extreme diameter of the thread. Major diameter minus minor diameter, divided by two, equals the height of the thread. The minor diameter of a nut is its inside diameter. The minor diameter of a bolt can be measured with go/no-go gauges or, directly, with an
1013:, together, would fully describe the thread form. Knowledge of PD determines the position of the sharp-V thread form, the sides of which coincide with the straight sides of the thread flanks: e.g., the crest of the external thread would truncate these sides a radial displacement
1983:
Screws" was developed to address this issue. Per the scope of the standard, it describes the gage and procedure for checking bolt and screw straightness at maximum material condition (MMC) and provides default limits when not stated in the applicable product standard.
811:
imply higher quality. The terms when used in reference to screw thread pitch have nothing to do with the tolerances used (degree of precision) or the amount of craftsmanship, quality, or cost. They simply refer to the size of the threads relative to the screw diameter.
983:
form of the thread, having flanks coincident with the flanks of the thread under test, at exactly 50% of its height. We have assumed that the flanks have the proper shape, angle, and pitch for the specified thread standard. It is generally unrelated to the major
1388:(ISO) in 1947. Although metric threads were mostly unified in 1898 by the International Congress for the standardization of screw threads, separate metric thread standards were used in France, Germany, and Japan, and the Swiss had a set of threads for watches.
485:
sometimes refer to all design aspects taken together (cross-sectional shape, pitch, and diameters), but commonly refer to the standardized geometry used by the screw. Major categories of threads include machine threads, material threads, and power threads.
1717:
1285:
series. The seal provided by a threaded pipe joint is created when a tapered externally threaded end is tightened into an end with internal threads. For most pipe joints, a good seal requires the application of a separate sealant into the joint, such as
669:"ridges" wrapped around the cylinder of the screw's body. Each time that the screw's body rotates one turn (360°), it has advanced axially by the width of two ridges. Another way to express this is that lead and pitch are parametrically related, and the
676:
Whereas metric threads are usually defined by their pitch, that is, how much distance per thread, inch-based standards usually use the reverse logic, that is, how many threads occur per a given distance. Thus, inch-based threads are defined in terms of
601:
876:), thread sizes are there to ensure that threads do not strip at the tensile strength limits for the parent material. The minimum limits for internal, and maximum limits for external, threads are there to ensure that the threads fit together.
1854:
thread standards were evolving, which usually employed 60° profiles. Some of these evolved into national or quasi-national standards. They were mostly unified in 1898 by the
International Congress for the standardization of screw threads at
394:
In artillery projectiles, anything that screws into the projectile must be given consideration as to what will happen when the projectile is fired, e.g., anything that screws into the base from the bottom of the projectile must be left hand
1781:
made interchangeable V-thread machine screws a practical commodity. During the next 40 years, standardization continued to occur on the intra- and inter-company levels. No doubt many mechanics of the era participated in this zeitgeist;
1250:. In the case of female threads, tap drill charts typically specify sizes that will produce an approximate 75% thread. A 60% thread may be appropriate in cases where high tensile loading will not be expected. In both cases, the
1206:
of the pitch from the dimension over the tips of the "fundamental" (sharp cornered) triangles. The resulting flats on the crests of the male thread are theoretically one eighth of the pitch wide (expressed with the notation
1415:, which has slightly different specifications, and has been technically obsolete since 1949. The old national standard is compatible with the newer unified standard, but is long out of date. This unified standard includes:
800:-20 belongs to the UNF series (Unified National Fine). Similarly, M10 (10 mm nominal outer diameter) as per ISO 261 has a coarse thread version at 1.5 mm pitch and a fine thread version at 1.25 mm pitch.
528:. Truncation occurs (and is codified in standards) for practical reasonsâthe thread-cutting or thread-forming tool cannot practically have a perfectly sharp point, and truncation is desirable anyway, because otherwise:
681:(TPI). Pitch and TPI describe the same underlying physical propertyâmerely in different terms. When the inch is used as the unit of measurement for pitch, TPI is the reciprocal of pitch and vice versa. For example, a
1178:
A perfectly sharp 60° V-thread will have a depth of thread ("height" from root to crest) equal to 0.866 of the pitch. This fact is intrinsic to the geometry of an equilateral triangle â a direct result of the basic
1753:
long-ago intracompany origins. For example, compare the 6â32, 8â32, 10â24, and 10â32 options in this table with the UTS versions of those sizes, which are not identical but are so close that interchange would work.
1123:. For imperial, H or L limits are used which designate how many units of 0.0005 inch over or undersized the pitch diameter is from its basic value, respectively. Thus a tap designated with an H limit of 3, denoted
1667:
Fahrradgewinde (Fg) (English: bicycle thread) is a German bicycle thread standard (per DIN 79012 and DIN 13.1), which encompasses a lot of CEI and BSC threads as used on cycles and mopeds everywhere (
1159:
To achieve a predictably successful mating of male and female threads and assured interchangeability between males and between females, standards for form, size, and finish must exist and be followed.
1960:
There are many ways to generate a screw thread, including the traditional subtractive types (for example, various kinds of cutting ; molding; casting ; forming and rolling; grinding; and occasionally
1396:
In particular applications and certain regions, threads other than the ISO metric screw threads remain commonly used, sometimes because of special application requirements, but mostly for reasons of
1254:
is not affected. The balancing of truncation versus thread strength is similar to many engineering decisions involving the strength, weight and cost of material, as well as the cost to machine it.
294:
By common convention, right-handedness is the default handedness for screw threads. Therefore, most threaded parts and fasteners have right-handed threads. Left-handed thread applications include:
380:
In a situation where neither threaded pipe end can be rotated to tighten or loosen the joint (e.g. in traditional heating pipes running through several rooms in a building). In such a case, the
1310:
understood the screw principle, and left drawings showing how threads could be cut by machine. In the 1500s, screws appeared in German watches, and were used to fasten suits of armor. In 1569,
1928:; U.S. auto parts factories long ago developed the ability to conform to the ISO standards, and today very few parts for new cars retain inch-based sizes, regardless of being made in the U.S.
1035:, or minimum difference, between the PDs of the internal and external threads has to generally be provided for, to eliminate the possibility of deviations from the ideal thread form causing
1031:
However, this ideal condition would in practice only be approximated and would generally require wrench-assisted assembly, possibly causing the galling of the threads. For this reason, some
542:
The roots and crests of mating male and female threads need clearance to ensure that the sloped sides of the V meet properly despite error in pitch diameter and dirt and nick-induced burrs.
1183:. It is independent of measurement units (inch vs mm). However, UTS and ISO threads are not sharp threads. The major and minor diameters delimit truncations on either side of the sharp V.
673:
that relates them, the number of starts, very often has a value of 1, in which case their relationship becomes equality. In general, lead is equal to pitch times the number of starts.
267:. Most threads are oriented so that the threaded item, when seen from a point of view on the axis through the center of the helix, moves away from the viewer when it is turned in a
1246:
in the case of female threads, or by slightly reducing the diameter of the threaded area of workpiece in the case of male threads, the latter effectively reducing the thread's
1235:
value. For example, a 75% thread sacrifices only a small amount of strength in exchange for a significant reduction in the force required to cut the thread. The result is that
1318:, but the method did not gain traction and screws continued to be made largely by hand for another 150 years. In the 1800s, screw manufacturing began in England during the
1649:
Aerospace inch threads (UNJ) â ISO 3161, controlled root radius on male threads for greater fatigue strength with larger minor diameter on female threads to clear radius.
524:
to varying degrees (that is, the tip of the triangle is cut short). A V-thread in which there is no truncation (or a minuscule amount considered negligible) is called a
1355:
Additional product standards identify preferred thread sizes for screws and nuts, as well as corresponding bolt head and nut sizes, to facilitate compatibility between
1797:. During the 1840s through 1860s, this standard was often used in the United States as well, in addition to myriad intra- and inter-company standards. In April 1864,
579:, but any angle can be used. The cross section to measure this angle lies on a plane which includes the axis of the cylinder or cone on which the thread is produced.
449:
Different (and incompatible) threads including (from left) M12 left hand, standard M12, M12x1.5 (fine), M12x1.25 (fine), 1/2" UNF, 1/2" UNC, 1/2" BSW, and 1/2" BSF
1385:
1352:
Standard threads are commonly identified by short letter codes (M, UNC, etc.) which also form the prefix of the standardized designations of individual threads.
1028:
root-crest clearances. This is the case when the flanks of the threads come into intimate contact with one another, before the roots and crests do, if at all.
816:
less likely to vibrate loose as they have a smaller helix angle and allow finer adjustment. Finer threads develop greater preload with less tightening torque.
1757:
1885:
in pursuit of reliable interchangeability. Classes of fit were standardized, and new ways of generating and inspecting screw threads were developed (such as
221:. Generally speaking, the threads on an external surface are considered male, while the ones on an internal surface are considered female. For example, a
2272:
1870:
created an "SAE series" of screw thread sizes reflecting parentage from earlier USS and
American Society of Mechanical Engineers (ASME) standards.
1130:
The pitch diameter of a thread is measured where the radial cross section of a single thread equals half the pitch, for example: 16 pitch thread =
1793:
created a design that, through its adoption by many
British railway companies, became a standard for the United Kingdom and British Empire called
860:: Industry standards specify minimum (min.) and maximum (max.) limits for each of these, for all recognized thread sizes. The minimum limits for
1175:
that can be expressed as a fraction of the pitch value. The UTS and ISO standards codify the amount of truncation, including tolerance ranges.
1052:
may even provide for negative allowances, where the PD of the screw is greater than the PD of the nut by at least the amount of the allowance.
2589:
2573:
2524:
2480:
1664:(Pg) (German) is an old German 80° thread (DIN 40430) that remained in use until 2000 in some electrical installation accessories in Germany.
1748:
A table of standard sizes for machine screws as provided by the
American Screw Company of Providence, Rhode Island, USA, and published in a
2395:"ASME 125th Anniversary: Special 2005 Designation of Landmarks: Profound Influences in Our Lives: The United States Standard Screw Threads"
1687:
995:) diameters, especially if the crest and root truncations of the sharp-V form at these diameters are unknown. Everything else being ideal,
165:
Both moving objects linearly and simultaneously measuring the movement, combining the two aforementioned functions, as in a leadscrew of a
1897:
was adopted by the Screw Thread
Standardization Committees of Canada, the United Kingdom, and the United States on November 18, 1949, in
298:
Where the rotation of a shaft would cause a conventional right-handed nut to loosen rather than to tighten due to applied torque or to
85:, which is the linear distance the screw travels in one revolution. In most applications, the lead of a screw thread is chosen so that
2659:
1171:
Screw threads are almost never made perfectly sharp (no truncation at the crest or root), but instead are truncated, yielding a final
1067:
3-wire method. Sometimes grease is used to hold the wires in place, helping the user to juggle the part, mic, and wires into position.
200:
2369:
Quentin R. Skrabec, Jr. (2005). "The
Metallurgic Age: The Victorian Flowering of Invention and Industrial Science". p. 169. McFarland
2178:
2608:
2499:
2211:
1836:
1733:
1493:
1408:
1322:. In these times, there was no such thing as standardization. The bolts made by one manufacturer would not fit the nuts of another.
1224:), although the actual geometry definition has more variables than that. A full (100%) UTS or ISO thread has a height of around 0.65
1063:, called a thread mic or pitch mic, which has a V-anvil and a conical spindle tip, contacts the thread flanks for a direct reading.
365:
In gas welding the flammable gas supply uses left-handed threads, while the oxygen supply if there is one has a conventional thread
2509:
Oberg, Erik; Jones, Franklin D.; Horton, Holbrook L.; Ryffel, Henry H. (1996), Green, Robert E.; McCauley, Christopher J. (eds.),
2101:
1825:(USS thread). Over the next 30 years the standard was further defined and extended and evolved into a set of standards including
2126:
2394:
2235:
615:
1909:
1822:
1513:
1482:
1467:
1378:
1282:
588:
1099:. Classes include 1, 2, 3 (loose to tight); A (external) and B (internal); and various systems such as H and D limits.
1548:
50:
structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a
1821:. Other firms adopted it, and it soon became a national standard for the U.S., later becoming generally known as the
897:
of the nut threads, one must also ensure that the clearances are not so excessive as to cause the fasteners to fail.
225:
has male threads, while its matching hole (whether in nut or substrate) has female threads. This property is called
2259:
1839:
were also developed and refined for small instrumentation and electrical equipment. These were based on the metric
1794:
1724:
1461:
1744:
957:
1977:
1953:
1728:
A good summary of screw thread standards in current use in 1914 was given in Colvin FH, Stanley FA (eds) (1914):
1556:
1519:
336:
91:
1886:
1850:
During this era, in continental Europe, the
British and American threadforms were well known, but also various
1814:
1343:
740:
1273:
used in some plumbing installations for the delivery of fluids under pressure have a threaded section that is
1196: in) threads is the theoretical major diameter of the male thread, which is truncated (diametrically) by
2511:
2013:
1894:
1677:
1404:
1374:
1368:
1180:
945:, due to the unused spaces between the threads, must be minimized so as not to overly weaken the fasteners.
914:
777:
657:
is the distance along the screw's axis that is covered by one complete rotation of the screw thread (360°).
299:
1705:
1998:
1965:
1474:
1397:
1262:
Tapered threads are used on fasteners and pipe. A common example of a fastener with a tapered thread is a
1084:
67:
1924:
of industries produces market pressure in favor of phasing out minority standards. A good example is the
1239:
wear is reduced, the likelihood of breakage is lessened and higher cutting speeds can often be employed.
1147:
in the pitch actual pitch diameter of the thread is measured at the radial cross section measures 0.03125
2546:
1818:
1319:
1306:, who briefly wrote on spirals as well as designed several simple devices applying the screw principle.
1096:
1874:
complicated analyses made clear the importance of variables such as pitch diameter and surface finish.
2053:
1432:
1278:
1231:
Threads can be (and often are) truncated a bit more, yielding thread depths of 60% to 75% of the 0.65
889:
made for the minor and pitch diameters of the threads. Besides providing for a clearance between the
506:
422:
280:
78:
539:
upon cutting, and will be too susceptible to additional future burring resulting from dents (nicks);
158:
Measuring by correlating linear motion to rotary motion (and simultaneously amplifying it), as in a
2230:. Giesecke, Frederick E. (Frederick Ernest), 1869-1953. (4th ed.). New York: Macmillan. 1987.
1941:
1925:
1778:
1699:
1315:
1060:
159:
51:
2080:
2649:
2542:
2445:
2427:
2253:
2043:
1890:
1802:
1536:
1071:
934:
595:
490:
346:
The hand-tightened nut holding the fan blade to the motor spindle in many designs of oscillating
2382:
961:
Variants of snug fit. Only threads with matched PDs are truly snug, axially as well as radially.
905:
445:
1863:
of the necessary retooling would drive some firms from profit to loss and hamper the economy.
271:
direction, and moves towards the viewer when it is turned counterclockwise. This is known as a
2604:
2585:
2569:
2561:
2552:
2530:
2520:
2495:
2476:
2241:
2231:
2207:
1867:
1762:
1497:
1407:(UTS), is the dominant thread standard used in the United States and Canada. It is defined in
1330:
1307:
1092:
765:
712:. Another wave analogy is that pitch and TPI are inverses of each other in a similar way that
653:
are closely related concepts. They can be confused because they are the same for most screws.
466:
405:
to cause the cross slide to move away from the operator when the leadscrew is turned clockwise
381:
71:
2345:
436:) have a left-hand thread to deter theft, because they cannot be used in other light fixtures
2516:
2048:
1898:
1790:
1578:
1562:
1531:
1287:
629:
1773:
The first historically important intra-company standardization of screw threads began with
1555:, is a special 0.8-inch diameter Ă 36 thread-per-inch (TPI) Whitworth thread form used for
885:(as it is obstructed by the threads themselves) but it may be tested with go/no-go gauges.
832:
2654:
1882:
1798:
1736:
standards are discussed. The SAE series was not mentionedâat the time this edition of the
1541:
1348:
1088:
824:
510:
429:
122:
90:
comparable to driving a wedge into a gap until it sticks fast through friction and slight
55:
2307:
1613:
suspension bolts (in some countries only; some have gone entirely metric, others such as
2074:
1441:
National Pipe Taper Fuel (NPTF), also known as
Dryseal, a better sealing version of NPT.
247:
2285:
2023:
1844:
1783:
1774:
1610:
1311:
704:
As the distance from the crest of one thread to the next, pitch can be compared to the
576:
118:
2643:
2028:
2018:
2008:
2003:
1921:
1851:
1683:
1661:
1485:(BSP) which exists in a taper and non taper variant; used for other purposes as well
1274:
1270:
402:
388:
316:
306:
152:
133:
129:
255:
2402:
2160:
2038:
1860:
1840:
1806:
1740:
was being compiled, they were either still in development or just newly introduced.
1087:
and friction, is classified (categorized) in thread standards. Achieving a certain
1043:, as ISO standards call them, are provided for in various degrees in corresponding
571:
The included angle characteristic of the cross-sectional shape is often called the
566:
554:
536:
409:
373:
340:
30:
1668:
1119:
is a standard used for classifying the tolerance of the thread pitch diameter for
1039:
and to expedite hand assembly up to the length of engagement. Such allowances, or
2470:
2105:
1729:
362:
In some gas supply connections to prevent dangerous misconnections, for example:
185:
https://en.wikipedia.org/search/?title=Screw_thread&action=edit§ion=1
27:
Helical structure used to convert between rotational and linear movement or force
2629:
2275:, 2007-03-05, Version 1.3. Table 3: The market share of each screw thread, p. 7.
2033:
1905:
1878:
1716:
1693:
1674:
1525:
1418:
Unified Coarse (UNC), the successor to the obsolete National Coarse (NC) thread.
1236:
1120:
780:) include a coarse pitch and a fine pitch for each major diameter. For example,
730:
661:
is the distance from the crest of one thread to the next one at the same point.
521:
433:
426:
418:
147:
Moving objects linearly by converting rotary motion to linear motion, as in the
17:
725:
This distinction is analogous to that between coarse teeth and fine teeth on a
2634:
1993:
1507:
1303:
1263:
1243:
1091:
requires the ability to work within tolerance ranges for dimension (size) and
910:
705:
550:
356:
263:
The helix of a thread can twist in two possible directions, which is known as
142:
110:
35:
2624:
2534:
2245:
1720:
Graphic representation of formulas for the pitches of threads of screw bolts
1614:
1421:
Unified Fine (UNF), the successor to the obsolete National Fine (NF) thread.
1291:
734:
713:
670:
600:
474:
369:
347:
343:
heads, so that the torque tends to tighten rather than loosen the connection
268:
242:
148:
1856:
1732:, New York and London, McGraw-Hill, pp. 16â22. USS, metric, Whitworth, and
514:
229:. Assembling a male-threaded fastener to a female-threaded one is called
470:
86:
1055:
The pitch diameter of external threads is measured by various methods:
412:
for the blade to move in the direction of a regulating right hand finger
1961:
773:
322:
310:
173:
In all of these applications, the screw thread has two main functions:
408:
The depth of cut screw of a "Bailey" (or "Stanley-Bailey") type metal
1356:
557:
use conventional thread forms and threaded rollers instead of balls.
329:
2565:
2456:
Wilson pp. 77â78 (page numbers may be from an earlier edition).
1765:
standards (including screw size standards), reported in the journal
845:
837:
619:
Up to four starts are labeled with different colors in this example.
2127:"Threaded stud / steel / clamping â S&W Manufacturing Co., Inc"
1605:-inch BSW (not common in the US, but used in the rest of the world)
1593:-inch BSW (not common in the US, but used in the rest of the world)
1409:
ANSI/ASME B1.1 Unified Inch Screw Threads, (UN and UNR Thread Form)
505:. For 60° V-threads, the isosceles triangle is, more specifically,
1756:
1743:
1723:
1715:
1617:
have reverted to the BSW threads, or have never fully converted):
1329:
1242:
This additional truncation is achieved by using a slightly larger
956:
904:
831:
823:
739:
614:
599:
444:
254:
246:
222:
166:
114:
47:
34:
Screw thread, used to convert torque into the linear force in the
29:
1581:(TPI) Unified Special thread (UNS, USA and the rest of the world)
611:
for two screw threads; one with one start and one with two starts
2556:
709:
545:
The point of the threadform adds little strength to the thread.
1908:. In 1947, the ISO was founded; and in 1960, the metric-based
726:
638:
1411:. In some cases products are still made according to the old
180:
It prevents linear motion without the corresponding rotation.
1877:
A tremendous amount of engineering work was done throughout
790:-13 belongs to the UNC series (Unified National Coarse) and
1186:
The nominal diameter of Metric (e.g. M8) and Unified (e.g.
1696:(ANSI/ASME B1.20.7-1991 ) for garden hoses and accessories
1095:. Defining and achieving classes of fit are important for
587:"Threads per inch" redirects here. For woven fabrics, see
453:
The cross-sectional shape of a thread is often called its
283:. Threads oriented in the opposite direction are known as
2568:); and by Lindsay Publications, Inc., Bradley, Illinois (
2490:
Degarmo, E. Paul; Black, J T.; Kohser, Ronald A. (2003),
1302:
The screw thread concept seems to have occurred first to
1083:
The way in which male and female fit together, including
532:
The cutting or forming tool's edge will break too easily;
502:
328:
The securing nut on some circular saw blades â the large
1906:
metric system was eclipsing inch-based measurement units
1048:
possible due to the margin of tolerance. A class called
2560:. Reprinted by McGraw-Hill, New York and London, 1926 (
1702:, a German metric thread used for measuring instruments
553:, the male-female pairs have bearing balls in between.
421:
lamps and fittings (such as those formerly used on the
184:
66:
thread. A screw thread is the essential feature of the
58:
in the form of a helix, with the former being called a
2286:"American National Standard vs. Unified Inch Standard"
384:
will have one right-handed and one left-handed thread.
691:-20 thread has 20 TPI, which means that its pitch is
1522:
threads (GPI), primarily for glass bottles and vials
807:
here does not mean lower quality, nor does the term
641:
635:
664:Because the vast majority of screw threadforms are
632:
1464:(BSW), and for other Whitworth threads including:
868:, in ISO terminology), and the maximum limits for
398:In mechanisms to give a more intuitive action as:
2551:, New Haven, Connecticut: Yale University Press,
575:. For most V-threads, this is standardized as 60
1503:British Standard Buttress Threads (BS 1657:1950)
754:-20 UNC (left, for aluminium cylinder head) and
589:Units of textile measurement § Thread count
2079:. John Wiley & sons, Incorporated. p.
1669:http://www.fahrradmonteur.de/fahrradgewinde.php
535:The part or fastener's thread crests will have
2437:
2435:
2206:(25 ed.). Industrial Press. p. 893.
1435:, used in North America for several purposes.
1386:International Organization for Standardization
2584:(23rd ed.), New York: Industrial Press,
1843:, but like Whitworth etc. were defined using
1074:may also be used to determine PD graphically.
828:The three diameters that characterize threads
391:, to provide a "secret" method of disassembly
177:It converts rotary motion into linear motion.
8:
1290:, or a liquid or paste pipe sealant such as
764:-28 UNF (right, for steel nut; from a 1960s
489:Most triangular threadforms are based on an
1978:Threading (manufacturing) § Inspection
1456:National Pipe Straight Hose coupling (NPSH)
1444:National Pipe Taper Railing fittings (NPTR)
844:There are three characteristic diameters (
733:, or between coarse grit and fine grit on
355:In combination with right-hand threads in
1827:National Coarse (NC), National Fine (NF),
1786:was one of those whom history has noted.
332:at startup should tend to tighten the nut
102:Screw threads have several applications:
2492:Materials and Processes in Manufacturing
1652:Aerospace metric threads (MJ) â ISO 5855
1450:National Pipe Straight Mechanical (NPSM)
979:away from it, the "PD line," slices the
2065:
1496:(BA), primarily electronic/electrical,
1373:The most common threads in use are the
1024:away from the position of the PD line.
136:to each other and to caps and fixtures.
2580:Ryffel, Henry H.; et al. (1988),
2331:
2251:
1964:to follow the other processes); newer
1447:National Pipe Straight Coupling (NPSC)
701:inch (0.050 in or 1.27 mm).
401:The leadscrew of the cross slide of a
2346:"Sewing Machine Thread (NĂ€hnorm 100)"
1868:Society of Automobile Engineers (SAE)
1730:American Machinists' Handbook, 2nd ed
1658:Metal bone screws (HA, HB) â ISO 5835
1646:Tapping screw threads (ST) â ISO 1478
1453:National Pipe Straight Locknut (NPSL)
387:In some instances, for example early
7:
2179:"Identifying threads and connectors"
1866:Sometime between 1912 and 1916, the
1473:Cycle Engineers' Institute (CEI) or
1160:
917:. Only the commonly used values for
520:The theoretical triangle is usually
325:on the left side of some automobiles
259:The right-hand rule of screw threads
251:Right- and left-handed screw threads
2635:NASA RP-1228 Fastener Design Manual
2601:Design Dimensioning and Tolerancing
2441:
2423:
2378:
1932:terminology is not always precise.
1887:production thread-grinding machines
1251:
1247:
2603:(4th ed.), Goodheart-Wilcox,
2548:English and American Tool Builders
1488:British Standard Pipe Taper (BSPT)
201:Gender of connectors and fasteners
25:
2161:"Coarse Threads vs. Fine Threads"
1837:British Association screw threads
1655:Tyre valve threads (V) â ISO 4570
1494:British Association screw threads
1413:American National Standard Series
928:differ between the two standards.
321:The axle nuts, or less commonly,
279:) thread, because it follows the
81:of a screw thread depends on its
2344:www.mipraso.de, Michael Prandl.
2306:www.mipraso.de, Michael Prandl.
1641:-inch BSW for heavier luminaires
1629:-inch BSW for lighter luminaires
1516:a fixed pitch 26 TPI thread
628:
2073:Burnham, Reuben Wesley (1915).
1384:These were standardized by the
772:The common V-thread standards (
205:Every matched pair of threads,
62:thread and the latter called a
2625:International Thread Standards
1904:However, internationally, the
1750:Mechanical Engineers' Handbook
1:
2090:– via Internet Archive.
2014:Metric: M Profile Thread Form
1910:International System of Units
1823:United States Standard thread
1777:around 1800, when the modern
1761:Survey results on the use of
941:radial movement. The reduced
744:Camshaft cover stud threaded
477:, or other shapes. The terms
315:The left grinding wheel on a
1968:; and combinations thereof.
1551:(RMS) thread, also known as
1483:British standard pipe thread
1359:(wrenches) and other tools.
893:of the bolt threads and the
716:are inverses of each other.
501:because of the shape of the
2515:(25th ed.), New York:
2202:Green, Robert, ed. (1996).
1835:Meanwhile, in Britain, the
1694:Hose Coupling Screw Threads
1557:microscope objective lenses
1549:Royal Microscopical Society
1500:and to mount optical lenses
1377:(M) for most purposes, and
965:The pitch diameter (PD, or
913:is the same as that of all
493:. These are usually called
300:fretting induced precession
2676:
2630:ModelFixings â Thread Data
2472:Design of Machine Elements
2076:Mathematics for Machinists
1975:
1951:
1831:National Pipe Taper (NPT).
1795:British Standard Whitworth
1712:History of standardization
1462:British Standard Whitworth
1366:
1341:
1161:Standardization of threads
593:
586:
564:
240:
198:
2660:Threading (manufacturing)
2599:Wilson, Bruce A. (2004),
2106:"Bicycle Glossary: Pedal"
2004:Dryseal Pipe Threads Form
1954:Threading (manufacturing)
1801:presented a paper to the
1520:Glass Packaging Institute
1438:National Pipe Taper (NPT)
1424:Unified Extra Fine (UNEF)
1338:, ISO metric screw thread
909:The basic profile of all
68:screw as a simple machine
1815:Baldwin Locomotive Works
1375:ISO metric screw threads
1344:List of thread standards
915:ISO metric screw threads
2494:(9th ed.), Wiley,
2273:ISO/TC/ 1 Business Plan
1895:Unified Thread Standard
1678:Incandescent light bulb
1405:Unified Thread Standard
1392:Other current standards
1369:ISO metric screw thread
1181:trigonometric functions
778:Unified Thread Standard
583:Lead, pitch, and starts
350:and floor standing fans
2469:Bhandari, V B (2007),
2258:: CS1 maint: others (
2131:www.directindustry.com
1999:British Standard Cycle
1770:
1754:
1741:
1721:
1514:British Standard Brass
1475:British Standard Cycle
1398:backward compatibility
1339:
1041:fundamental deviations
962:
929:
841:
840:in a technical drawing
829:
769:
620:
612:
450:
260:
252:
213:, can be described as
39:
2350:www.gewinde-normen.de
2312:www.gewinde-normen.de
1918:SystĂšme International
1819:Pennsylvania Railroad
1760:
1747:
1727:
1719:
1706:Sewing machine thread
1506:British Standard for
1468:British Standard Fine
1427:Unified Special (UNS)
1333:
1320:Industrial Revolution
960:
908:
835:
827:
743:
618:
603:
448:
432:rolling stock of the
258:
250:
33:
2582:Machinery's Handbook
2512:Machinery's Handbook
2475:, Tata McGraw-Hill,
2228:Engineering graphics
2204:Machinery's Handbook
2054:Thread-locking fluid
2019:National Thread Form
1942:engineering drawings
1684:Fire hose connection
1433:National pipe thread
1363:ISO standard threads
1163:is discussed below.
1117:pitch diameter limit
1059:A dedicated type of
714:period and frequency
423:New York City Subway
302:. Examples include:
281:right-hand grip rule
79:mechanical advantage
2543:Roe, Joseph Wickham
2183:Essentra Components
1994:Anti-seize compound
1966:additive techniques
1936:Engineering drawing
1926:automotive industry
1891:optical comparators
1779:screw-cutting lathe
1680:holder screw thread
1316:screw-cutting lathe
1277:. Examples are the
141:Gear reduction via
92:elastic deformation
2308:"Löwenherz Thread"
2044:Thread pitch gauge
1881:and the following
1803:Franklin Institute
1771:
1755:
1742:
1722:
1537:Square thread form
1498:moving coil meters
1381:(R, G) for pipes.
1340:
1155:Interchangeability
1097:interchangeability
1072:optical comparator
963:
943:material condition
935:optical comparator
930:
842:
830:
770:
720:Coarse versus fine
621:
613:
596:Lead (engineering)
513:, the triangle is
491:isosceles triangle
451:
359:and clamping studs
261:
253:
113:, plastic screws,
109:Fasteners such as
40:
2591:978-0-8311-1200-4
2574:978-0-917914-73-7
2526:978-0-8311-2575-2
2482:978-0-07-061141-2
2150:Bhandari, p. 205.
1563:Microphone stands
1308:Leonardo da Vinci
1103:Tolerance classes
72:threaded fastener
16:(Redirected from
2667:
2613:
2595:
2559:
2538:
2517:Industrial Press
2505:
2485:
2457:
2454:
2448:
2439:
2430:
2421:
2415:
2414:
2412:
2410:
2401:. Archived from
2391:
2385:
2376:
2370:
2367:
2361:
2360:
2358:
2356:
2341:
2335:
2329:
2323:
2322:
2320:
2318:
2303:
2297:
2296:
2294:
2292:
2282:
2276:
2270:
2264:
2263:
2257:
2249:
2224:
2218:
2217:
2199:
2193:
2192:
2190:
2189:
2175:
2169:
2168:
2157:
2151:
2148:
2142:
2141:
2139:
2137:
2123:
2117:
2116:
2114:
2113:
2098:
2092:
2091:
2089:
2087:
2070:
2049:Thread protector
1916:from the French
1899:Washington, D.C.
1791:Joseph Whitworth
1700:Löwenherz thread
1640:
1639:
1635:
1628:
1627:
1623:
1604:
1603:
1599:
1592:
1591:
1587:
1579:threads per inch
1576:
1575:
1571:
1532:Acme thread form
1288:thread seal tape
1275:slightly conical
1216:
1215:
1211:
1205:
1204:
1200:
1195:
1194:
1190:
1150:
1146:
1142:
1139:
1138:
1134:
1050:interference fit
799:
798:
794:
789:
788:
784:
766:Jaguar XK engine
763:
762:
758:
753:
752:
748:
700:
699:
695:
690:
689:
685:
679:threads per inch
648:
647:
644:
643:
640:
637:
634:
511:buttress threads
21:
18:Left-hand thread
2675:
2674:
2670:
2669:
2668:
2666:
2665:
2664:
2640:
2639:
2621:
2611:
2598:
2592:
2579:
2541:
2527:
2508:
2502:
2489:
2483:
2468:
2465:
2460:
2455:
2451:
2440:
2433:
2422:
2418:
2408:
2406:
2405:on 13 June 2005
2393:
2392:
2388:
2377:
2373:
2368:
2364:
2354:
2352:
2343:
2342:
2338:
2334:, p. 1603.
2330:
2326:
2316:
2314:
2305:
2304:
2300:
2290:
2288:
2284:
2283:
2279:
2271:
2267:
2250:
2238:
2226:
2225:
2221:
2214:
2201:
2200:
2196:
2187:
2185:
2177:
2176:
2172:
2159:
2158:
2154:
2149:
2145:
2135:
2133:
2125:
2124:
2120:
2111:
2109:
2108:. Sheldon Brown
2100:
2099:
2095:
2085:
2083:
2072:
2071:
2067:
2063:
2058:
1989:
1980:
1974:
1956:
1950:
1938:
1883:interwar period
1799:William Sellers
1714:
1637:
1633:
1632:
1625:
1621:
1620:
1601:
1597:
1596:
1589:
1585:
1584:
1573:
1569:
1568:
1542:Buttress thread
1394:
1371:
1365:
1349:Standardization
1346:
1328:
1326:Standardization
1300:
1260:
1213:
1209:
1208:
1202:
1198:
1197:
1192:
1188:
1187:
1169:
1157:
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1136:
1132:
1131:
1110:
1105:
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1023:
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994:
978:
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955:
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903:
882:
822:
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792:
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786:
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781:
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746:
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722:
697:
693:
692:
687:
683:
682:
631:
627:
598:
592:
585:
569:
563:
443:
430:Sprague-Thomson
335:The spindle on
307:left foot pedal
245:
239:
203:
197:
192:
100:
28:
23:
22:
15:
12:
11:
5:
2673:
2671:
2663:
2662:
2657:
2652:
2642:
2641:
2638:
2637:
2632:
2627:
2620:
2619:External links
2617:
2616:
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2609:
2596:
2590:
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2500:
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2102:Brown, Sheldon
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2059:
2057:
2056:
2051:
2046:
2041:
2036:
2031:
2029:Tapered thread
2026:
2024:Nut (hardware)
2021:
2016:
2011:
2006:
2001:
1996:
1990:
1988:
1985:
1976:Main article:
1973:
1970:
1952:Main article:
1949:
1946:
1937:
1934:
1845:Imperial units
1784:Joseph Clement
1775:Henry Maudslay
1713:
1710:
1709:
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1681:
1672:
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1642:
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1611:Stage lighting
1608:
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1553:society thread
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1393:
1390:
1367:Main article:
1364:
1361:
1342:Main article:
1334:An example of
1327:
1324:
1299:
1296:
1271:threaded pipes
1259:
1256:
1252:pitch diameter
1248:major diameter
1168:
1165:
1156:
1153:
1109:
1106:
1104:
1101:
1093:surface finish
1080:
1079:Classes of fit
1077:
1076:
1075:
1068:
1064:
1021:
1010:
999:
992:
976:
969:
954:
953:Pitch diameter
951:
921:
902:
901:Minor diameter
899:
881:
880:Major diameter
878:
858:pitch diameter
854:minor diameter
850:major diameter
848:) of threads:
821:
818:
721:
718:
594:Main article:
584:
581:
565:Main article:
562:
559:
547:
546:
543:
540:
533:
526:sharp V-thread
461:(also spelled
442:
439:
438:
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406:
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392:
389:ballpoint pens
385:
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241:Main article:
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139:
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130:threaded pipes
126:
115:machine screws
99:
96:
70:and also as a
26:
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14:
13:
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9:
6:
4:
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2:
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2610:1-59070-328-6
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2507:
2503:
2501:0-471-65653-4
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2215:
2213:0-8311-2575-6
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2052:
2050:
2047:
2045:
2042:
2040:
2037:
2035:
2032:
2030:
2027:
2025:
2022:
2020:
2017:
2015:
2012:
2010:
2009:Filter thread
2007:
2005:
2002:
2000:
1997:
1995:
1992:
1991:
1986:
1984:
1979:
1971:
1969:
1967:
1963:
1958:
1955:
1948:Manufacturing
1947:
1945:
1943:
1935:
1933:
1929:
1927:
1923:
1922:Globalization
1919:
1915:
1912:(abbreviated
1911:
1907:
1902:
1900:
1896:
1892:
1888:
1884:
1880:
1875:
1871:
1869:
1864:
1862:
1858:
1853:
1848:
1846:
1842:
1838:
1833:
1832:
1828:
1824:
1820:
1816:
1810:
1808:
1804:
1800:
1796:
1792:
1787:
1785:
1780:
1776:
1768:
1767:Horseless Age
1764:
1759:
1751:
1746:
1739:
1735:
1731:
1726:
1718:
1711:
1707:
1704:
1701:
1698:
1695:
1692:
1690:standard 194)
1689:
1685:
1682:
1679:
1676:
1673:
1670:
1666:
1663:
1662:Panzergewinde
1660:
1657:
1654:
1651:
1648:
1645:
1631:
1619:
1618:
1616:
1612:
1609:
1595:
1583:
1580:
1567:
1566:
1564:
1561:
1558:
1554:
1550:
1547:
1543:
1540:
1538:
1535:
1533:
1530:
1529:
1527:
1524:
1521:
1518:
1515:
1512:
1509:
1505:
1502:
1499:
1495:
1492:
1487:
1486:
1484:
1481:
1476:
1472:
1469:
1466:
1465:
1463:
1460:
1455:
1452:
1449:
1446:
1443:
1440:
1437:
1436:
1434:
1431:
1426:
1423:
1420:
1417:
1416:
1414:
1410:
1406:
1403:
1402:
1401:
1399:
1391:
1389:
1387:
1382:
1380:
1376:
1370:
1362:
1360:
1358:
1353:
1350:
1345:
1337:
1332:
1325:
1323:
1321:
1317:
1314:invented the
1313:
1309:
1305:
1297:
1295:
1293:
1289:
1284:
1280:
1276:
1272:
1267:
1265:
1257:
1255:
1253:
1249:
1245:
1240:
1238:
1234:
1229:
1227:
1223:
1219:
1184:
1182:
1176:
1174:
1166:
1164:
1162:
1154:
1152:
1128:
1126:
1122:
1118:
1114:
1107:
1102:
1100:
1098:
1094:
1090:
1086:
1078:
1073:
1069:
1065:
1062:
1058:
1057:
1056:
1053:
1051:
1046:
1042:
1038:
1034:
1029:
1025:
1020:
1017: â
1016:
1009:
1005:
998:
991:
988:) and minor (
987:
982:
975:
968:
959:
952:
950:
946:
944:
938:
936:
927:
920:
916:
912:
907:
900:
898:
896:
892:
886:
879:
877:
875:
871:
867:
863:
859:
855:
851:
847:
839:
834:
826:
819:
817:
813:
810:
806:
801:
779:
775:
767:
742:
738:
736:
732:
728:
719:
717:
715:
711:
707:
702:
680:
674:
672:
667:
662:
660:
656:
652:
646:
625:
617:
610:
606:
602:
597:
590:
582:
580:
578:
574:
568:
560:
558:
556:
555:Roller screws
552:
544:
541:
538:
534:
531:
530:
529:
527:
523:
518:
516:
512:
508:
504:
500:
496:
492:
487:
484:
480:
476:
472:
468:
465:). It may be
464:
460:
456:
447:
440:
435:
431:
428:
424:
420:
416:
411:
407:
404:
400:
399:
397:
393:
390:
386:
383:
379:
375:
374:LPG cylinders
371:
367:
364:
363:
361:
358:
354:
349:
345:
342:
338:
334:
331:
327:
324:
320:
318:
317:bench grinder
314:
312:
308:
304:
303:
301:
297:
296:
295:
292:
290:
286:
282:
278:
274:
270:
266:
257:
249:
244:
236:
234:
232:
228:
224:
220:
216:
212:
208:
202:
194:
189:
187:
186:
179:
176:
175:
174:
168:
164:
161:
157:
154:
150:
146:
144:
140:
135:
131:
127:
124:
120:
116:
112:
108:
107:
105:
104:
103:
97:
95:
93:
88:
84:
80:
75:
73:
69:
65:
61:
57:
53:
49:
45:
37:
32:
19:
2600:
2581:
2547:
2510:
2491:
2471:
2452:
2428:pp. 248â249.
2419:
2407:. Retrieved
2403:the original
2398:
2389:
2374:
2365:
2353:. Retrieved
2349:
2339:
2327:
2315:. Retrieved
2311:
2301:
2289:. Retrieved
2280:
2268:
2227:
2222:
2203:
2197:
2186:. Retrieved
2182:
2173:
2164:
2155:
2146:
2134:. Retrieved
2130:
2121:
2110:. Retrieved
2096:
2084:. Retrieved
2075:
2068:
2039:Thread angle
1981:
1959:
1957:
1940:In American
1939:
1930:
1917:
1913:
1903:
1876:
1872:
1865:
1861:capital cost
1849:
1841:Thury thread
1834:
1830:
1826:
1811:
1807:Philadelphia
1788:
1772:
1766:
1749:
1737:
1552:
1412:
1395:
1383:
1372:
1354:
1347:
1335:
1301:
1268:
1261:
1241:
1232:
1230:
1225:
1221:
1217:
1185:
1177:
1173:thread depth
1172:
1170:
1167:Thread depth
1158:
1129:
1124:
1116:
1113:Thread limit
1112:
1111:
1108:Thread limit
1089:class of fit
1082:
1054:
1049:
1044:
1040:
1037:interference
1036:
1032:
1030:
1026:
1018:
1014:
1007:
1003:
996:
989:
985:
980:
973:
966:
964:
947:
942:
939:
931:
925:
918:
894:
890:
887:
883:
873:
869:
865:
861:
857:
853:
849:
843:
814:
808:
804:
802:
771:
723:
703:
678:
675:
666:single-start
665:
663:
658:
654:
650:
623:
622:
608:
604:
573:thread angle
572:
570:
567:Thread angle
548:
525:
519:
498:
494:
488:
482:
478:
462:
458:
454:
452:
410:plane (tool)
341:line trimmer
293:
288:
284:
276:
273:right-handed
272:
264:
262:
230:
226:
218:
214:
210:
206:
204:
183:
172:
101:
98:Applications
82:
76:
63:
59:
44:screw thread
43:
41:
2332:Ryffel 1988
2165:katonet.com
2034:Tap and die
1879:World War I
1675:Edison base
1526:Power screw
1508:Spark Plugs
1379:BSP threads
1237:tap and die
1143:in = 0.0625
911:UTS threads
551:ball screws
507:equilateral
499:vee-threads
475:trapezoidal
463:thread form
434:Paris Metro
427:World War I
425:or the pre-
419:Edison base
357:turnbuckles
337:brushcutter
285:left-handed
143:worm drives
128:Connecting
111:wood screws
106:Fastening:
2644:Categories
2463:References
2237:0023427604
2188:2021-03-05
2112:2010-10-19
1972:Inspection
1510:BS 45:1972
1304:Archimedes
1264:wood screw
1061:micrometer
706:wavelength
483:threadform
471:triangular
459:threadform
348:table fans
265:handedness
237:Handedness
160:micrometer
36:flood gate
2650:Fasteners
2535:473691581
2383:pp. 9â10.
2254:cite book
1789:In 1841,
1615:Australia
1577:-inch 27
1292:pipe dope
1244:tap drill
1033:allowance
820:Diameters
803:The term
735:sandpaper
671:parameter
522:truncated
495:V-threads
370:POL valve
269:clockwise
243:Chirality
149:leadscrew
2566:27-24075
2557:16011753
2545:(1916),
2442:Roe 1916
2424:Roe 1916
2399:asme.org
2379:Roe 1916
2246:13498926
1987:See also
1817:and the
1738:Handbook
1528:threads
1357:spanners
1220:or 0.125
1006:, &
870:internal
862:external
503:letter V
395:threaded
382:coupling
323:lug nuts
211:internal
207:external
87:friction
60:straight
52:cylinder
2446:p. 249.
2409:4 April
2355:4 April
2317:4 April
2136:4 April
2086:4 April
1962:lapping
1636:⁄
1624:⁄
1600:⁄
1588:⁄
1572:⁄
1298:History
1212:⁄
1201:⁄
1191:⁄
1135:⁄
1045:classes
981:sharp-V
795:⁄
785:⁄
774:ISO 261
759:⁄
749:⁄
696:⁄
686:⁄
577:degrees
515:scalene
311:bicycle
64:tapered
48:helical
2655:Screws
2607:
2588:
2572:
2564:
2555:
2533:
2523:
2498:
2479:
2291:14 Mar
2244:
2234:
2210:
1857:ZĂŒrich
1852:metric
1769:, 1916
1312:Besson
1149:
1145:
1141:
856:, and
805:coarse
649:) and
509:. For
467:square
330:torque
231:mating
227:gender
219:female
195:Gender
190:Design
121:, and
2061:Notes
1477:(BSC)
1470:(BSF)
1258:Taper
1199:0.866
891:crest
836:Sign
708:of a
659:Pitch
651:pitch
609:pitch
561:Angle
537:burrs
417:Some
403:lathe
309:on a
223:screw
167:lathe
151:of a
134:hoses
123:bolts
46:is a
2605:ISBN
2586:ISBN
2570:ISBN
2562:LCCN
2553:LCCN
2531:OCLC
2521:ISBN
2496:ISBN
2477:ISBN
2411:2018
2357:2018
2319:2018
2293:2019
2260:link
2242:OCLC
2232:ISBN
2208:ISBN
2138:2018
2088:2018
1889:and
1829:and
1688:NFPA
1281:and
1269:The
1151:in.
1121:taps
1085:play
924:and
895:root
866:bolt
864:(or
809:fine
776:and
731:file
710:wave
655:Lead
624:Lead
607:and
605:Lead
481:and
479:form
455:form
441:Form
372:for
368:The
339:and
305:The
217:and
215:male
209:and
153:jack
132:and
119:nuts
83:lead
77:The
56:cone
2081:137
1805:in
1763:SAE
1336:M16
1283:BSP
1279:NPT
1115:or
1070:An
922:maj
874:nut
729:or
727:saw
549:In
497:or
457:or
291:).
54:or
2646::
2576:).
2529:,
2519:,
2444:,
2434:^
2426:,
2397:.
2381:,
2348:.
2310:.
2256:}}
2252:{{
2240:.
2181:.
2163:.
2129:.
2104:.
1914:SI
1847:.
1734:BA
1565::
1400::
1294:.
1266:.
1228:.
1193:16
1137:16
1125:H3
1002:,
937:.
852:,
737:.
698:20
639:iË
517:.
473:,
469:,
289:LH
277:RH
233:.
117:,
94:.
74:.
42:A
2614:.
2594:.
2537:.
2504:.
2486:.
2413:.
2359:.
2321:.
2295:.
2262:)
2248:.
2216:.
2191:.
2167:.
2140:.
2115:.
1686:(
1671:)
1638:2
1634:1
1626:8
1622:3
1602:8
1598:3
1590:4
1586:1
1574:8
1570:5
1559:.
1233:p
1226:p
1222:p
1218:p
1214:8
1210:1
1203:4
1189:5
1133:1
1022:2
1019:D
1015:D
1011:1
1008:D
1004:D
1000:2
997:D
993:1
990:D
986:D
984:(
977:2
974:D
970:2
967:D
926:P
919:D
872:(
846:â
838:â
797:2
793:1
787:2
783:1
768:)
761:4
757:1
751:4
747:1
694:1
688:4
684:1
645:/
642:d
636:l
633:Ë
630:/
626:(
591:.
287:(
275:(
169:.
162:.
155:.
125:.
20:)
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