ASME B18.21.1 Helical Spring Lock Washers

ASME B18.21.1 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 Helical Spring Lock Washers

ASME B18.21.1 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 4.369 0.508 0.889 0.61
ASME B18.21.1 #3 (0.099) 2.718 2.565 4.953 0.635 1.016 0.711
ASME B18.21.1 #4 (0.112) 3.048 2.896 5.309 0.635 1.016 0.711
ASME B18.21.1 #5 (0.125) 3.378 3.226 5.994 0.787 1.194 0.838
ASME B18.21.1 #6 (0.138) 3.759 3.581 6.35 0.787 1.194 0.838
ASME B18.21.1 #8 (0.164) 4.42 4.242 7.442 1.016 1.397 0.965
ASME B18.21.1 #10 (0.190) 5.08 4.902 8.484 1.194 1.575 1.092
ASME B18.21.1 #12 (0.216) 5.766 5.588 9.576 1.422 1.778 1.245
ASME B18.21.1 1⁄4 (0.250) 6.604 6.401 12.37 1.575 2.769 1.93
ASME B18.21.1 5⁄16 (0.3125) 8.179 7.976 14.808 1.981 3.175 2.21
ASME B18.21.1 3⁄8 (0.375) 9.779 9.576 17.272 2.388 3.581 2.515
ASME B18.21.1 7⁄16 (0.4375) 11.43 11.176 19.71 2.769 3.962 2.769
ASME B18.21.1 1⁄2 (0.500) 13.005 12.751 22.073 3.175 4.343 3.048
ASME B18.21.1 9⁄16 (0.5625) 14.58 14.326 24.511 3.581 4.775 3.353
ASME B18.21.1 5⁄8 (0.625) 16.281 15.951 27.254 3.962 5.156 3.607
ASME B18.21.1 11⁄16 (0.6875) 17.882 17.551 29.718 4.369 5.563 3.886
ASME B18.21.1 3⁄4 (0.750) 19.456 19.126 32.131 4.775 5.944 4.166
ASME B18.21.1 13⁄16 (0.8125) 21.133 20.726 34.62 5.156 6.35 4.445
ASME B18.21.1 7⁄8 (0.875) 22.708 22.301 37.059 5.563 6.756 4.724
ASME B18.21.1 15⁄16 (0.9375) 24.333 23.901 39.522 5.944 7.137 5.004
ASME B18.21.1 1 (1.000) 26.01 25.476 42.062 6.35 7.544 5.283
ASME B18.21.1 11⁄16 (1.0625) 27.61 27.076 44.475 6.756 7.925 5.537
ASME B18.21.1 11⁄8 (1.125) 29.286 28.677 46.914 7.137 8.331 5.842
ASME B18.21.1 13⁄16 (1.1875) 30.912 30.277 49.352 7.544 8.738 6.121
ASME B18.21.1 11⁄4 (1.250) 32.512 31.852 51.714 7.925 9.119 6.375
ASME B18.21.1 15⁄16 (1.3125) 34.138 33.452 54.178 8.331 9.525 6.655
ASME B18.21.1 13⁄8 (1.375) 35.763 35.027 56.363 8.738 9.931 6.96
ASME B18.21.1 17⁄16 (1.4375) 37.389 36.627 59.03 9.119 10.312 7.214
ASME B18.21.1 11⁄2 (1.500) 38.964 38.202 61.443 9.525 10.719 7.493
ASME B18.21.1 15⁄8 (1.625) 42.24 41.478 64.846 9.881 10.77 7.544
ASME B18.21.1 13⁄4 (1.750) 45.441 44.653 68.047 9.881 10.77 7.544
ASME B18.21.1 17⁄8 (1.875) 48.616 47.828 71.399 10.719 10.846 7.595
ASME B18.21.1 2 (2.000) 51.791 51.003 74.574 10.719 10.846 7.595
ASME B18.21.1 21⁄4 (2.250) 58.242 57.455 81.813 11.176 11.227 7.849
ASME B18.21.1 21⁄2 (2.500) 64.592 63.805 88.163 11.176 11.227 7.849
ASME B18.21.1 23⁄4 (2.750) 70.942 70.155 97.13 11.633 12.471 8.738
ASME B18.21.1 3 (3.000) 77.292 76.505 103.48 11.633 12.471 8.738
  • aT = mean section thickness = (ti + to) ÷ 2.

ASME B18.21.1 Helical Spring Lock Washers (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 4.369 0.508 0.889 0.61
ASME B18.21.1 #3 (0.099) 2.718 2.565 4.953 0.635 1.016 0.711
ASME B18.21.1 #4 (0.112) 3.048 2.896 5.309 0.635 1.016 0.711
ASME B18.21.1 #5 (0.125) 3.378 3.226 5.994 0.787 1.194 0.838
ASME B18.21.1 #6 (0.138) 3.759 3.581 6.35 0.787 1.194 0.838
ASME B18.21.1 #8 (0.164) 4.42 4.242 7.442 1.016 1.397 0.965
ASME B18.21.1 #10 (0.190) 5.08 4.902 8.484 1.194 1.575 1.092
ASME B18.21.1 #12 (0.216) 5.766 5.588 9.576 1.422 1.778 1.245
ASME B18.21.1 1⁄4 (0.250) 6.604 6.401 12.37 1.575 2.769 1.93
ASME B18.21.1 5⁄16 (0.3125) 8.179 7.976 14.808 1.981 3.175 2.21
ASME B18.21.1 3⁄8 (0.375) 9.779 9.576 17.272 2.388 3.581 2.515
ASME B18.21.1 7⁄16 (0.4375) 11.43 11.176 19.71 2.769 3.962 2.769
ASME B18.21.1 1⁄2 (0.500) 13.005 12.751 22.073 3.175 4.343 3.048
ASME B18.21.1 9⁄16 (0.5625) 14.58 14.326 24.511 3.581 4.775 3.353
ASME B18.21.1 5⁄8 (0.625) 16.281 15.951 27.254 3.962 5.156 3.607
ASME B18.21.1 11⁄16 (0.6875) 17.882 17.551 29.718 4.369 5.563 3.886
ASME B18.21.1 3⁄4 (0.750) 19.456 19.126 32.131 4.775 5.944 4.166
ASME B18.21.1 13⁄16 (0.8125) 21.133 20.726 34.62 5.156 6.35 4.445
ASME B18.21.1 7⁄8 (0.875) 22.708 22.301 37.059 5.563 6.756 4.724
ASME B18.21.1 15⁄16 (0.9375) 24.333 23.901 39.522 5.944 7.137 5.004
ASME B18.21.1 1 (1.000) 26.01 25.476 42.062 6.35 7.544 5.283
ASME B18.21.1 11⁄16 (1.0625) 27.61 27.076 44.475 6.756 7.925 5.537
ASME B18.21.1 11⁄8 (1.125) 29.286 28.677 46.914 7.137 8.331 5.842
ASME B18.21.1 13⁄16 (1.1875) 30.912 30.277 49.352 7.544 8.738 6.121
ASME B18.21.1 11⁄4 (1.250) 32.512 31.852 51.714 7.925 9.119 6.375
ASME B18.21.1 15⁄16 (1.3125) 34.138 33.452 54.178 8.331 9.525 6.655
ASME B18.21.1 13⁄8 (1.375) 35.763 35.027 56.363 8.738 9.931 6.96
ASME B18.21.1 17⁄16 (1.4375) 37.389 36.627 59.03 9.119 10.312 7.214
ASME B18.21.1 11⁄2 (1.500) 38.964 38.202 61.443 9.525 10.719 7.493
ASME B18.21.1 15⁄8 (1.625) 42.24 41.478 64.846 9.881 10.77 7.544
ASME B18.21.1 13⁄4 (1.750) 45.441 44.653 68.047 9.881 10.77 7.544
ASME B18.21.1 17⁄8 (1.875) 48.616 47.828 71.399 10.719 10.846 7.595
ASME B18.21.1 2 (2.000) 51.791 51.003 74.574 10.719 10.846 7.595
ASME B18.21.1 21⁄4 (2.250) 58.242 57.455 81.813 11.176 11.227 7.849
ASME B18.21.1 21⁄2 (2.500) 64.592 63.805 88.163 11.176 11.227 7.849
ASME B18.21.1 23⁄4 (2.750) 70.942 70.155 97.13 11.633 12.471 8.738
ASME B18.21.1 3 (3.000) 77.292 76.505 103.48 11.633 12.471 8.738
  • aT = mean section thickness = (ti + to) ÷ 2.

ASME Material Specifications

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EN Material Specifications

ISO Material Specifications