ASME B18.21.1 Extra Duty Helical Spring Lock Washers

ASME B18.21.1 Extra Duty Helical Spring Lock Washers Standard covers the dimensional requirements, physical properties, and related test methods for helical spring-lock washers (#0 through 3 in.), tooth-lock washers (#2 through 1 3/4 in.), and plain washers (#0 through 3 in.).
The inclusion of dimensional data in ASME B18.21.1 Standard is not intended to imply that all products described are stock production items. Consumers should consult with suppliers concerning the availability of products.

ASME B18.21.1 Extra Duty Helical Spring Lock Washers

ASME B18.21.1 Extra Duty Helical Spring Lock Washers Dimensions (mm)

Nominal Size Inside Diameter, A Maximum Outside Diameter, B Minimum Mean Section Thickness (ti + to)/2, T Minimum Section Width, W Minimum Bearing Width, BW
Max. Min.
ASME B18.21.1 #2 (0.086) 2.388 2.235 5.283 0.686 1.346 0.94
ASME B18.21.1 #3 (0.099) 2.718 2.565 6.071 0.864 1.575 1.092
ASME B18.21.1 #4 (0.112) 3.048 2.896 6.426 0.864 1.575 1.092
ASME B18.21.1 #5 (0.125) 3.378 3.226 7.62 1.143 2.007 1.397
ASME B18.21.1 #6 (0.138) 3.759 3.581 7.976 1.143 2.007 1.397
ASME B18.21.1 #8 (0.164) 4.42 4.242 9.525 1.448 2.438 1.702
ASME B18.21.1 #10 (0.190) 5.08 4.902 11.024 1.727 2.845 1.981
ASME B18.21.1 #12 (0.216) 5.766 5.588 12.624 2.032 3.302 2.311
ASME B18.21.1 1⁄4 (0.250) 6.604 6.401 13.538 2.134 3.353 2.337
ASME B18.21.1 5⁄16 (0.3125) 8.179 7.976 15.723 2.743 3.632 2.54
ASME B18.21.1 3⁄8 (0.375) 9.779 9.576 18.745 3.124 4.318 3.023
ASME B18.21.1 7⁄16 (0.4375) 11.43 11.176 21.234 3.632 4.724 3.302
ASME B18.21.1 1⁄2 (0.500) 13.005 12.751 23.749 4.115 5.182 3.632
ASME B18.21.1 9⁄16 (0.5625) 14.58 14.326 26.289 4.623 5.664 3.962
ASME B18.21.1 5⁄8 (0.625) 16.281 15.951 29.235 5.131 6.147 4.293
ASME B18.21.1 11⁄16 (0.6875) 17.882 17.551 31.801 5.613 6.604 4.623
ASME B18.21.1 3⁄4 (0.750) 19.456 19.126 34.417 6.121 7.087 4.953
ASME B18.21.1 13⁄16 (0.8125) 21.133 20.726 37.033 6.629 7.569 5.309
ASME B18.21.1 7⁄8 (0.875) 22.708 22.301 39.903 7.239 8.179 5.715
ASME B18.21.1 15⁄16 (0.9375) 24.333 23.901 42.774 7.823 8.763 6.121
ASME B18.21.1 1 (1.000) 26.01 25.476 45.568 8.382 9.296 6.502
ASME B18.21.1 11⁄16 (1.0625) 27.61 27.076 48.387 8.941 9.881 6.909
ASME B18.21.1 11⁄8 (1.125) 29.286 28.677 51.13 9.525 10.439 7.315
ASME B18.21.1 13⁄16 (1.1875) 30.912 30.277 53.518 10.058 10.947 7.671
ASME B18.21.1 11⁄4 (1.250) 32.512 31.852 56.439 10.592 11.481 8.026
ASME B18.21.1 15⁄16 (1.3125) 34.138 33.452 59.106 11.125 11.989 8.382
ASME B18.21.1 13⁄8 (1.375) 35.763 35.027 61.697 11.633 12.471 8.738
ASME B18.21.1 17⁄16 (1.4375) 37.389 36.627 64.262 12.141 12.929 9.042
ASME B18.21.1 11⁄2 (1.500) 38.964 38.202 66.726 12.598 13.36 9.347
ASME B18.21.1 15⁄8 (1.625) 42.24 41.478 70.714 12.598 13.36 9.347
ASME B18.21.1 13⁄4 (1.750) 45.441 44.653 73.711 13.36 13.513 9.449
ASME B18.21.1 17⁄8 (1.875) 48.616 47.828 76.886 13.36 13.513 9.449
ASME B18.21.1 2 (2.000) 51.791 51.003 80.162 13.36 13.513 9.449
  • aT = mean section thickness = (ti + to) ÷ 2.

ASME B18.21.1 Extra Duty Helical Spring Lock Washers Dimensions (Inch)

Nominal Size Inside Diameter, A Maximum Outside Diameter, B Minimum Mean Section Thickness (ti + to)/2, T Minimum Section Width, W Minimum Bearing Width, BW
Max. Min.
ASME B18.21.1 #2 (0.086) 2.388 2.235 5.283 0.686 1.346 0.94
ASME B18.21.1 #3 (0.099) 2.718 2.565 6.071 0.864 1.575 1.092
ASME B18.21.1 #4 (0.112) 3.048 2.896 6.426 0.864 1.575 1.092
ASME B18.21.1 #5 (0.125) 3.378 3.226 7.62 1.143 2.007 1.397
ASME B18.21.1 #6 (0.138) 3.759 3.581 7.976 1.143 2.007 1.397
ASME B18.21.1 #8 (0.164) 4.42 4.242 9.525 1.448 2.438 1.702
ASME B18.21.1 #10 (0.190) 5.08 4.902 11.024 1.727 2.845 1.981
ASME B18.21.1 #12 (0.216) 5.766 5.588 12.624 2.032 3.302 2.311
ASME B18.21.1 1⁄4 (0.250) 6.604 6.401 13.538 2.134 3.353 2.337
ASME B18.21.1 5⁄16 (0.3125) 8.179 7.976 15.723 2.743 3.632 2.54
ASME B18.21.1 3⁄8 (0.375) 9.779 9.576 18.745 3.124 4.318 3.023
ASME B18.21.1 7⁄16 (0.4375) 11.43 11.176 21.234 3.632 4.724 3.302
ASME B18.21.1 1⁄2 (0.500) 13.005 12.751 23.749 4.115 5.182 3.632
ASME B18.21.1 9⁄16 (0.5625) 14.58 14.326 26.289 4.623 5.664 3.962
ASME B18.21.1 5⁄8 (0.625) 16.281 15.951 29.235 5.131 6.147 4.293
ASME B18.21.1 11⁄16 (0.6875) 17.882 17.551 31.801 5.613 6.604 4.623
ASME B18.21.1 3⁄4 (0.750) 19.456 19.126 34.417 6.121 7.087 4.953
ASME B18.21.1 13⁄16 (0.8125) 21.133 20.726 37.033 6.629 7.569 5.309
ASME B18.21.1 7⁄8 (0.875) 22.708 22.301 39.903 7.239 8.179 5.715
ASME B18.21.1 15⁄16 (0.9375) 24.333 23.901 42.774 7.823 8.763 6.121
ASME B18.21.1 1 (1.000) 26.01 25.476 45.568 8.382 9.296 6.502
ASME B18.21.1 11⁄16 (1.0625) 27.61 27.076 48.387 8.941 9.881 6.909
ASME B18.21.1 11⁄8 (1.125) 29.286 28.677 51.13 9.525 10.439 7.315
ASME B18.21.1 13⁄16 (1.1875) 30.912 30.277 53.518 10.058 10.947 7.671
ASME B18.21.1 11⁄4 (1.250) 32.512 31.852 56.439 10.592 11.481 8.026
ASME B18.21.1 15⁄16 (1.3125) 34.138 33.452 59.106 11.125 11.989 8.382
ASME B18.21.1 13⁄8 (1.375) 35.763 35.027 61.697 11.633 12.471 8.738
ASME B18.21.1 17⁄16 (1.4375) 37.389 36.627 64.262 12.141 12.929 9.042
ASME B18.21.1 11⁄2 (1.500) 38.964 38.202 66.726 12.598 13.36 9.347
ASME B18.21.1 15⁄8 (1.625) 42.24 41.478 70.714 12.598 13.36 9.347
ASME B18.21.1 13⁄4 (1.750) 45.441 44.653 73.711 13.36 13.513 9.449
ASME B18.21.1 17⁄8 (1.875) 48.616 47.828 76.886 13.36 13.513 9.449
ASME B18.21.1 2 (2.000) 51.791 51.003 80.162 13.36 13.513 9.449
  • aT = mean section thickness = (ti + to) ÷ 2.

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EN Material Specifications

ISO Material Specifications