563:
101:
605:. One of the plates is held stationary while the other rotates. The top plate has an opening to allow balls to enter and exit the rill plates. These plates have fine circumferential grooves that the balls track in. The balls are run through the machine long enough so that each ball passes through many of these grooves, which ensures each ball is the same size, even if a particular groove is out of specification. The controllable machine variables are the amount of pressure applied, the speed of the plates, and how long the balls are left in the machine.
695:
43:
660:, again in the same type of machine. However, this time the rill plates are made of a softer material, usually cast iron, less pressure is applied, the plate is rotated slowly. This step is what gives bearing balls their shiny appearance and can bring the balls between grades 10 and 48.
153:. The grades range from 2000 to 3, where the smaller the number the higher the precision. Grades are written "GXXXX", i.e. grade 100 would be "G100". Lower grades also have fewer defects, such as flats, pits, soft spots, and cuts. The surface smoothness is measured in two ways:
192:
refers to the amount of deviation from a true spherical form (out of roundness). This is measured by rotating a ball against a linear transducer with a gauge force of less than 4 grams (0.14 oz). The resulting
652:. They are ground in the same type of machine as used before, but either an abrasive is introduced into the coolant or the rotating plate is replaced with a very hard fine-grain
164:
Size refers to the farthest possible distance between two points on the ball's surface, as measured by two parallel plates in contact with the surface. The starting size is the
53:
562:
135:
1472:
1548:
1380:
1510:
1415:
138:(ABMA), a body which sets standards for the precision of bearing balls. They are manufactured in machines designed specially for the job.
201:
with the smallest circle possible and the difference between this circumscribed circle and the nominal ball diameter is the variation.
1596:
87:
100:
1586:
1581:
630:
process afterward to improve precision. This is done in the same type of machine, but the rill plates are replaced with
656:. This step can get the balls within ±0.0001 in (0.0025 mm). If the balls need more precision, then they are
626:
671:
69:
578:
176:, which is the difference between the largest and smallest diameter measurement. For a given lot there is a
150:
1478:
694:
586:
1591:
1554:
663:
If even more precision is needed, then proprietary chemical and mechanical processes are usually used.
1386:
126:
mechanisms. The balls themselves are commonly referred to as ball bearings. This is an example of a
65:
1421:
554:
The manufacture of bearing balls depends on the type of material the balls are being made from.
1506:
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780:
860:
764:
711:
104:
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598:
1575:
710:
materials that are then ground to size and shape as above. Common materials include:
638:
768:
760:
617:
612:
is pumped between the rill plates because the high pressure between the plates and
198:
172:, or theoretical, ball diameter. The ball size is then determined by measuring the
119:
31:
194:
149:
Bearing balls are manufactured to a specific grade, which defines its geometric
1449:
616:
creates considerable heat. The high pressure applied to the balls also induces
581:
to give a pellet with a volume approximately that of the ball with the desired
1354:
1296:
667:
188:
127:
776:
642:
594:
123:
27:
Machine component most commonly used as the rolling element in ball bearings
17:
589:
into a rough spherical shape. Next, the balls are fed into a machine that
169:
1451:
How do they get the balls in ball bearings so perfectly round and smooth?
792:
784:
707:
613:
590:
158:
1526:
824:
808:
796:
657:
609:
686:
Plastic bearing balls are made in the same manner as described above.
816:
800:
593:
them. The machine does this by feeding the balls between two heavy
820:
804:
772:
693:
570:
561:
99:
141:
In 2008, the United States produced 5.778 billion bearing balls.
812:
788:
574:
181:
115:
1349:
Ball
Definitions - The specification defines three parameters:
184:
diameter of the largest ball and the smallest ball of the lot.
1499:
Ley, Wilfried; Wittmann, Klaus; Hallmann, Willi (2009-06-16).
1357:. The surface integrity refers to surface smoothness, hardness
36:
1474:
Production
Process for a standard grade 24, Chrome Steel ball
52:
deal primarily with the United States and do not represent a
61:
829:
389:
203:
107:bearing balls, in diameters ranging from 1 to 20mm
134:. These grades are defined by bodies such as the
670:of bearing balls was one of the case studies in
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831:Material comparison for common bearing balls
122:, but also used as components in things like
50:The examples and perspective in this article
8:
1410:
1408:
1406:
1404:
1402:
623:Sometimes the balls are then run through a
1283:Where 1 is the lowest and 5 is the highest
136:American Bearing Manufacturers Association
88:Learn how and when to remove this message
114:are special highly spherical and smooth
1308:
1267:
799:. Other less common materials include
645:to remove any residue or by-products.
180:, which is the difference between the
1444:
1442:
1440:
1438:
637:If the balls are steel they are then
7:
676:Principles of Scientific Management
130:. The balls come in many different
706:Ceramic bearing balls are made of
391:Grade tolerances for metric sizes
25:
641:. After heat treatment they are
408:Maximum surface roughness (Ra)
405:Nominal ball diameter tolerance
225:Maximum surface roughness (Ra)
222:Nominal ball diameter tolerance
205:Grade tolerances for inch sizes
41:
620:, which strengthens the balls.
1331:MA332Q - Antifriction Bearings
1:
1502:Handbook of space technology
64:, discuss the issue on the
1613:
585:(OD). This pellet is then
29:
759:Common materials include
1597:Rolling-element bearings
1184:5 in (130 mm)
1172:1.5 in (38 mm)
1113:Electrical Conductivity
672:Frederick Winslow Taylor
118:, most commonly used in
30:Not to be confused with
1189:Relative load capacity
402:Lot diameter variation
219:Lot diameter variation
174:ball diameter variation
1227:Relative fatigue life
703:
567:
178:lot diameter variation
108:
1587:Hardware (mechanical)
1582:Bearings (mechanical)
961:Corrosion resistance
698:Zirconium dioxide ZrO
697:
608:During the operation
565:
166:nominal ball diameter
103:
842:Stainless steel 440C
70:create a new article
62:improve this article
1550:Ball Material Types
923:Temperature limit
832:
648:The balls are then
392:
206:
1454:, 15 November 2000
830:
704:
568:
390:
204:
109:
1512:978-0-470-69739-9
1351:surface integrity
1264:
1263:
737:zirconium dioxide
573:balls start as a
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546:
388:
387:
155:surface roughness
98:
97:
90:
72:, as appropriate.
16:(Redirected from
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1553:, archived from
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1420:, archived from
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1385:, archived from
1382:ABMA Definitions
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1336:US Census Bureau
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781:tungsten carbide
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1319:Merriam Webster
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765:stainless steel
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712:silicon nitride
701:
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632:grinding stones
601:plates, called
560:
552:
168:, which is the
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105:Silicon nitride
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1175:No Torque Tube
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1137:Non-conductive
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654:grinding wheel
599:hardened steel
583:outer diameter
577:. The wire is
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56:of the subject
54:worldwide view
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3:
2:
1609:
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1577:
1557:on 2008-02-28
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1519:
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1481:on 2008-05-17
1480:
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1445:
1443:
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1435:
1424:on 2009-05-07
1423:
1419:
1418:
1417:Manufacturing
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1405:
1403:
1399:
1389:on 2009-10-08
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1037:Availability
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786:
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766:
762:
754:
752:
738:
713:
709:
702:bearing balls
696:
689:
687:
681:
679:
677:
673:
669:
664:
661:
659:
655:
651:
646:
644:
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629:
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621:
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564:
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555:
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531:
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200:
199:circumscribed
196:
191:
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185:
183:
179:
175:
171:
167:
162:
160:
156:
152:
144:
142:
139:
137:
133:
129:
125:
121:
120:ball bearings
117:
113:
112:Bearing balls
106:
102:
92:
89:
81:
71:
67:
63:
57:
55:
48:
39:
38:
33:
19:
1592:Metalworking
1559:, retrieved
1555:the original
1549:
1543:
1532:, retrieved
1527:
1521:
1501:
1494:
1483:, retrieved
1479:the original
1473:
1467:
1456:, retrieved
1450:
1426:, retrieved
1422:the original
1416:
1391:, retrieved
1387:the original
1381:
1353:, size, and
1345:
1330:
1324:
1315:
1311:
1102:Non-magnetic
1099:Non-magnetic
1096:Non-magnetic
769:chrome steel
761:carbon steel
758:
705:
685:
675:
665:
662:
649:
647:
639:heat treated
636:
624:
622:
618:cold working
607:
602:
569:
553:
187:
186:
177:
173:
165:
163:
148:
140:
131:
111:
110:
84:
78:October 2014
75:
51:
32:Ball bearing
18:Bearing ball
1151:Size limit
1146:Conductive
674:'s classic
650:hard ground
603:rill plates
566:Rill plates
550:Manufacture
399:Sphericity
216:Sphericity
213:Size range
195:polar graph
1576:Categories
1561:2010-10-06
1534:2009-07-03
1485:2009-07-02
1458:2009-07-01
1428:2009-07-02
1393:2009-11-16
1355:sphericity
1303:References
1297:Steel shot
1143:Conductive
1140:Conductive
1134:Conductive
1131:Conductive
1128:Conductive
1125:Conductive
1122:Conductive
1119:Conductive
1116:Conductive
885:Hardness
668:inspection
591:de-flashes
189:Sphericity
151:tolerances
128:synecdoche
1528:Materials
1505:. Wiley.
1108:Magnetic
1075:Magnetic
857:Haynes 25
839:UNS 52100
777:aluminium
755:Materials
595:cast iron
124:freewheel
66:talk page
1291:See also
1105:Magnetic
1093:Magnetic
1090:Magnetic
1087:Magnetic
1084:Magnetic
1081:Magnetic
1078:Magnetic
836:Material
793:titanium
785:platinum
708:sintered
643:descaled
627:grinding
614:friction
373:0.006–10
353:0.006–10
333:0.006–10
313:0.006–10
299:0.000025
296:0.000025
293:0.006–10
273:0.006–10
262:±0.00005
259:0.000005
256:0.000005
242:±0.00003
239:0.000003
236:0.000003
197:is then
159:waviness
60:You may
854:440NDUR
825:niobium
809:k-monel
797:plastic
690:Ceramic
682:Plastic
610:coolant
579:sheared
507:±0.0127
490:±0.0051
473:±0.0025
456:±0.0013
453:0.00025
450:0.00025
439:±0.0013
436:0.00013
433:0.00013
422:±0.0008
419:0.00008
416:0.00008
342:±0.0005
322:±0.0003
319:0.00005
316:0.00005
302:±0.0001
282:±0.0001
279:0.00001
276:0.00001
253:0.006–6
233:0.006–2
170:nominal
1509:
1338:, 2008
851:REX-20
823:, and
817:silver
801:copper
735:) and
658:lapped
587:headed
541:±0.127
527:0.203
524:±0.025
510:0.127
504:0.0025
501:0.0025
493:0.076
487:0.0012
484:0.0012
476:0.051
470:0.0006
467:0.0006
459:0.025
425:0.012
382:±0.005
362:±0.001
359:0.0002
356:0.0002
339:0.0001
336:0.0001
132:grades
999:Cost
956:1000
880:C276
848:BG-42
821:glass
805:monel
773:brass
625:soft
571:Metal
558:Metal
538:0.025
535:0.025
521:0.005
518:0.005
442:0.02
396:Grade
379:0.001
376:0.001
210:Grade
145:Grade
116:balls
68:, or
1507:ISBN
1181:None
1178:None
1169:None
1166:None
1163:None
1160:None
1157:None
1154:None
947:1500
944:1200
873:BeCu
813:lead
789:gold
666:The
575:wire
532:1000
370:1000
365:8.0
345:5.0
325:3.0
305:2.0
285:1.0
265:0.8
245:0.5
182:mean
157:and
953:500
950:400
941:300
938:600
935:400
932:400
929:300
926:300
918:40
877:455
845:M50
751:).
741:ZrO
597:or
515:200
498:100
350:200
330:100
1578::
1437:^
1401:^
1362:^
1334:,
1270:^
1260:1
1222:1
1070:4
1032:4
994:5
915:50
912:40
909:70
906:50
903:60
900:66
897:62
894:62
891:58
888:60
861:Si
827:.
819:,
815:,
811:,
807:,
803:,
795:,
791:,
787:,
783:,
779:,
775:,
771:,
767:,
763:,
716:Si
678:.
634:.
481:50
464:25
447:10
310:50
290:25
270:10
161:.
1565:.
1538:.
1515:.
1489:.
1462:.
1432:.
1340:.
1257:1
1254:1
1251:5
1248:1
1245:3
1242:5
1239:4
1236:4
1233:2
1230:3
1219:1
1216:1
1213:5
1210:1
1207:3
1204:5
1201:4
1198:4
1195:2
1192:3
1067:2
1064:3
1061:3
1058:5
1055:4
1052:2
1049:2
1046:2
1043:1
1040:1
1029:2
1026:3
1023:5
1020:5
1017:1
1014:3
1011:2
1008:1
1005:1
1002:1
991:4
988:1
985:5
982:5
979:4
976:1
973:2
970:1
967:3
964:1
867:4
865:N
863:3
746:2
739:(
730:4
725:N
721:3
714:(
700:2
430:5
413:3
250:5
230:3
91:)
85:(
80:)
76:(
58:.
34:.
20:)
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