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Split Lock Washer

Selected Split Helical Lock Washer BlackSplit Lock Washer
Split Helical Lock Washer BlackSplit Lock Washer

Low carbon split lock washers are used under bolt heads or nuts to increase the hold of the fastener or to increase the bearing surface. Split lock washers are helical-shaped split rings. When fastened, the two ends exert a spring force on the fastener to create increased friction and resistance to motion. Dimensional specifications are governed by ASME B18.21.1.

Products

Governing Standards

ASME B18.21.1 Covers the dimensional requirements, physical properties, and related test methods for helical spring-lock washers (#0 through 3 inches), tooth-lock washers (#2 through 1 ¼ inches), and plain washers (#0 through 3 inches).

Dimensional Specifications

Split Lock Washer dimensions
Per ASME B18.21.1-2009
Size Nominal A B T W BW
Inside
Diameter		 Outside
Diameter		 Mean Section
Thickness		 Section
Width		 Bearing
Width
Max Min Max Min Min Min
#2 0.0860 0.0940 0.0880 0.1720 0.0200 0.0350 0.0240
#3 0.0990 0.1070 0.1010 0.1950 0.0250 0.0400 0.0280
#4 0.1120 0.1200 0.1140 0.2090 0.0250 0.0400 0.0280
#5 0.1250 0.1330 0.1270 0.2360 0.0310 0.0470 0.0330
#6 0.1380 0.1480 0.1410 0.2500 0.0310 0.0470 0.0330
#8 0.1640 0.1740 0.1670 0.2930 0.0400 0.0550 0.0380
#10 0.1900 0.2000 0.1930 0.3340 0.0470 0.0620 0.0430
#12 0.2160 0.2270 0.2200 0.3770 0.0560 0.0700 0.0490
1/4 0.2500 0.2600 0.2520 0.4870 0.0620 0.1090 0.0760
5/16 0.3125 0.3220 0.3140 0.5830 0.0780 0.1250 0.0870
3/8 0.3750 0.3850 0.3770 0.6800 0.0940 0.1410 0.0990
7/16 0.4375 0.4500 0.4400 0.7760 0.1090 0.1560 0.1090
1/2 0.5000 0.5120 0.5020 0.8690 0.1250 0.1710 0.1200
9/16 0.5625 0.5740 0.5640 0.9650 0.1410 0.1880 0.1320
5/8 0.6250 0.6410 0.6280 1.0730 0.1560 0.2090 0.1420
3/4 0.7500 0.7660 0.7530 1.2650 0.1880 0.2340 0.1640
7/8 0.8750 0.8940 0.8780 1.4590 0.2190 0.2660 0.1860
1 1.0000 1.0240 1.0030 1.6560 0.2500 0.2970 0.2080
1 1/8 1.1250 1.1530 1.1290 1.8470 0.2810 0.3280 0.2300
1 1/4 1.2500 1.2800 1.2540 2.0360 0.3120 0.3590 0.2510
1 3/8 1.3750 1.4080 1.3790 2.2190 0.3440 0.3910 0.2740
1 1/2 1.5000 1.5340 1.5040 2.4190 0.3750 0.4220 0.2950
1 5/8 1.6250 1.6630 1.6330 2.5530 0.3890 0.4240 0.2970
1 3/4 1.7500 1.7890 1.7580 2.6790 0.3890 0.4240 0.2970
1 7/8 1.8750 1.9140 1.8830 2.8110 0.4220 0.4270 0.2990
2 2.0000 2.0390 2.0080 2.9360 0.4220 0.4270 0.2990
2 1/4 2.2500 2.2930 2.2620 3.2210 0.4400 0.4420 0.3090
2 1/2 2.5000 2.5430 2.5120 3.4710 0.4400 0.4420 0.3090
2 3/4 2.7500 2.7930 2.7620 3.8240 0.4580 0.4910 0.3440
3 3.0000 3.0430 3.0120 4.0740 0.4580 0.4910 0.3440
  1. All dimensions are in inches.