217:
443:.) The typical threading depth for #4-40 UNC jackposts used in PCs is 3/16" (0.1875 inches or 4.76 millimetres); the jackscrews that go into them are typically somewhat longer. The length of hexagonal jackpost heads can vary slightly, though pairs should be identical. Generally the D-shell stands somewhat proud of these hex bolts. Occasionally the #4-40 hexagonal standoffs come loose when loosening the #4-40 screws to remove a cable, gender changer, or adapter. Care should however be taken not to overtighten standoffs as they are somewhat delicate and will snap off at the base with excessive torque.
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240:(threads per inch) which equates to a thread pitch of 0.031250 inches (0.7938 mm). The optional UNC specification indicates the standard coarse thread is used which is defined for #6 screws as 32 tpi rendering 'UNC' redundant, however it may be seen when other specifications such as plating or other treatments are also specified. It is by far the most common screw found inside computer cases. It commonly appears in lengths of
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drive is used instead. All three patterns may also be combined with a slot for a flat-blade screwdriver. Usually they are provided with a 1/4 in (0.25 inches (6.4 mm)) flanged hex head. Non-standard metricized 5.5 millimetres (0.22 in) flanged hex heads can also be encountered. Also common
468:
The M3 is a thinner screw with a finer thread than the #6-32 UNC. This makes it more suitable for fastening into smaller parts and thinner materials requiring good strength in a limited space. Its size and fine thread make it appropriate for applications where a #6-32 UNC would be excessively bulky
322:
specifying a nominal diameter of 3 millimetres (0.12 in); and standard coarse thread pitch defined as 0.5 millimetres (0.020 in). The M3 is the second most common screw found in PCs. It commonly appears in many lengths from 1 to 20 mm. Nearly every brand-new computer case comes with a bag
430:
Typically #4-40 UNC standoffs are used, which present the same #4-40 type female threading at their bolt end that they also screw into with their male end. These standoffs may also be called jackposts. They are similar but generally not identical to motherboard standoffs. The bolt end is typically
370:
Usually, the standoff has a #6-32 UNC male thread on one end which screws into a threaded hole in the case or motherboard backplate and a #6-32 UNC female thread in the other end which accepts a screw to retain the motherboard. Less often, the standoff has a female thread in both ends and a second
460:
The #6-32 UNC is a thicker screw with a more coarse thread. This makes it more suitable for fastening larger parts and thicker materials requiring increased holding strength. Its larger size and coarse thread make it easier to work with during assembly, with less risk of cross threading. The
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All-metric standoffs are stated as threading x hex length x threaded length. For example, M3 x 10 x 6 means a standoff with M3 male and female threading, 10 mm hex length, and 6 mm threaded length. M6 x 10 x 8 means M6 male and female threading, 10 mm hex length, and 8 mm threaded length.
367:. Sometimes threaded or snap-lock plastic standoffs are used, which are less secure, but equally useful in a stationary computer. The standoff provides a margin of space between the motherboard and the case to keep the multiple solder points below from grounding and short-circuiting.
252:(0.3125 inches (7.94 mm)). Non-standard metricized lengths such as 5 millimetres (0.20 in) are also sometimes encountered. Nearly every brand new computer case comes with a bag of these. They are commonly used for the following purposes, however there are many exceptions:
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specification states that the length of standoffs needs to be at least 0.25 inches (6.4 mm), with their cross sections fitting within 0.40 by 0.40 inches (10 mm Ă— 10 mm) square areas centered around each mounting hole on ATX motherboards.
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Steel is by far the most common material used, frequently with a plated or anodized finish. Other materials including brass, aluminum, nylon and various plastics are also used for applications with particular physical or aesthetic requirements.
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hex-shaped, but may exceptionally be round to make removal more difficult. The hex diameter is 3/16", or 4.7mm. A 5mm hex socket might still fit, however where tightening or removal is required, care needs to be taken to select a
362:
Most cases use threaded brass standoffs (Jack Screw
Standoffs) for attaching the motherboard to the case chassis. Because the case material is usually a conductive metal, attaching the motherboard directly to it can cause a
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outer edge. Because they are used in places where high torque is not required and easy removal and replacement may be desirable (such as on the side panels of the PC case), they are frequently available as
371:
screw is used to attach it to the case. Some standoffs use the M3 female thread (which faces the motherboard) instead of #6-32 UNC, and on a rare occasion a mixture of types can be used in the same case.
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Typically, M2.5 and M3 standoffs tighten with a 5 mm socket, M4 standoffs with a 6 mm socket, M5 standoffs with a 7 mm socket, and M6 standoffs with an 8 mm socket, but this is not always the case.
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diameter, as clearance between the jackpost and subminiature connector D-shell is limited. (A 9mm outer diameter should still fit, but 3/8" might already be marginally too big, depending on
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The M3 screw (bottom) has a thread pitch of 0.5 millimetres (0.020 in), which is finer than the 0.031250 inches (0.7938 mm) pitch of a #6-32 UNC screw (top).
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integrated flange provides greater holding strength with less risk of pull through. The hex head makes it easier to work with during assembly with
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410:. The derivation of the customary term "jackscrew" in this context is unclear. The screws are typically thumbscrews, but may be slotted or
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define preferred size combinations that are based on generic units—some on the inch and others on the millimetre.
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414:, especially where permanent attachment is expected, or where the heads need to be lower-profile to save space.
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150:. Although there are numerous manufacturers of computer cases, they have generally used three thread sizes. The
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and other circuit boards often use a #6-32 UNC standoff. #4-40 UNC thumb screws are often found on the ends of
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A male DE-9 connector showing hex jackposts on either side of the D-shell. Note the limited clearance.
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of these. Notwithstanding many exceptions, they are commonly used for securing the following devices:
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653:"ATX Specification, Version 2.1: Section 3.4.2 Secondary (Bottom/Solder) Side Height Constraints"
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Close-up of a #6-32 UNC screw with a flanged hex/Phillips head, commonly provided in PC cases
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208:) and enthusiast cases will lack screws altogether, instead utilizing a toolless design.
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and the case's body to secure the covers. The M3 threaded holes are often found on 5.25"
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Close-up of a #6-32 UNC screw with a
Phillips pan head, commonly provided in PC cases
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From left to right: a #6-32 UNC thumbscrew, a #6-32 UNC screw, an M3 screw and a
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with larger, knurled heads that can be removed with one's fingers or tools.
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633:"Which screws do I use to install the motherboard onto the standoffs?"
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usually, one or more #6-32 UNC screws hold the main cover on the case
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21 phillips screw 6-32 × 5 mm for motherboard, 3.5” harddisk tray
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7 thumb screw 6-32 × 6 mm for 2.5” drive tray, expansion slots
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without providing any other benefits versus the smaller M3.
399:. These fasteners are typically located on either side of
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M3 screws typically accept a #2 Phillips screwdriver tip.
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Pairs of #4-40 UNC jackscrews are used to fasten certain
546:
1 positioning standoff 6-32 Ă— 6.5 + 4 mm for motherboard
403:
connectors, such as on VGA, DVI, serial, parallel and
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which is defined as 0.1380 inches (3.51 mm); and
154:(UTS) originates from the United States, while the
49:. Unsourced material may be challenged and removed.
16:Hardware used to secure parts of a PC to the case
259:securing a 3.5-inch hard disk drive to the case
596:"2.5-inch Hard Disk Drives Installation Guide"
537:12 phillips screw M3 × 5 mm for 2.5” harddrive
200:More modern cases from certain manufacturers (
165:The #6-32 UNC screws are often found on 3.5"
8:
720:The 11 Tools Every System Builder Should Own
543:9 standoff 6-32 Ă— 6.5 + 4 mm for motherboard
524:A regular computer case may require/include
142:are the hardware used to secure parts of a
574:
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276:They are almost always provided with a #2
248:(0.25 inches (6.4 mm)) or less often
220:The #6-32 UNC screw has a thread pitch of
158:is standardized worldwide. In turn, these
109:Learn how and when to remove this message
662:. 2012-08-18. p. 18. Archived from
269:fastening case components to one another
568:
476:
358:Various types of motherboard standoffs
232:specifying a major thread diameter of
7:
47:adding citations to reliable sources
531:4 hexagon screw 6-32 Ă— 6 mm for psu
256:securing a power supply to the case
244:(0.1875 inches (4.76 mm)) and
224:(0.031250 inches (0.7938 mm)).
605:. January 30, 2007. Archived from
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266:in place by its metal slot cover
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34:needs additional citations for
1:
463:powered torque screwdrivers
293:screws - a low disk with a
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435:with a sufficiently small
723:(and screws) from crn.com
280:drive. Sometimes a Green
510:Thumbscrews from an ATX
441:manufacturing tolerances
333:2.5-inch hard disks and
581:Dan's Data - Letters 53
540:16 KB5 x 10 mm for fans
156:ISO metric screw thread
152:Unified Thread Standard
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58:"Computer case screws"
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408:game controller ports
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631:admin (2022-03-11).
612:on December 24, 2012
387:#4-40 UNC jackscrews
350:Motherboard standoff
43:improve this article
378:Version 2.1 of the
329:optical disc drives
228:The #6-32 UNC is a
177:, and 2.5" drives.
171:optical disc drives
737:Computer enclosure
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688:"H500 Manual"
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669:on 2016-08-17
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54:Find sources:
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32:This article
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698:. Retrieved
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671:. Retrieved
664:the original
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636:. Retrieved
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616:November 16,
614:. Retrieved
607:the original
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585:, 2006-02-26
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320:metric screw
318:The M3 is a
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197:connectors.
179:Motherboards
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127:self-tapping
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41:Please help
36:verification
33:
583:, "Screwed"
300:thumbscrews
262:holding an
731:Categories
673:2014-12-22
638:2022-03-22
563:References
456:Comparison
433:nut driver
393:connectors
327:5.25-inch
129:screw for
69:newspapers
418:Jackposts
339:3.5-inch
295:chamfered
282:Robertson
230:UTS screw
131:case fans
551:See also
447:Material
306:M3 screw
291:pan head
278:Phillips
195:parallel
700:17 June
520:Example
473:Gallery
250:5/16 in
242:3/16 in
222:1/32 in
206:Gateway
173:, 3.5"
146:to the
83:scholar
742:Screws
405:legacy
246:1/4 in
238:32 tpi
191:serial
139:screws
85:
78:
71:
64:
56:
691:(PDF)
667:(PDF)
656:(PDF)
610:(PDF)
599:(PDF)
437:outer
90:JSTOR
76:books
702:2021
695:NZXT
618:2014
603:HGST
557:Torx
514:case
289:are
286:Torx
202:Dell
193:and
148:case
62:news
395:to
380:ATX
284:or
187:VGA
183:DVI
45:by
733::
693:.
658:.
601:.
571:^
512:PC
465:.
234:#6
204:,
189:,
185:,
144:PC
704:.
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106:(
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97:(
87:·
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39:.
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