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ASME B18.21.1 Internal External Tooth Lock Washers

ASME B18.21.1 Internal External Tooth 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 Internal External Tooth Lock Washers

ASME B18.21.1 Internal External Tooth Lock Washers Dimensions (mm)

Nominal Size Inside Diameter, A Outside Diameter, B Thickness, C
Max. Min. Max. Min. Max. Min.
ASME B18.21.1 #4 (0.112) 3.124 2.921 12.065 11.684 0.533 0.406
12.954 12.573 0.533 0.431
15.494 14.732 0.533 0.431
ASME B18.21.1 #6 (0.138) 3.81 3.581 12.954 12.573 0.711 0.584
15.494 14.732 0.711 0.584
17.526 17.018 0.711 0.584
ASME B18.21.1 #8 (0.164) 4.47 4.267 15.494 14.732 0.863 0.711
17.526 17.018 0.863 0.711
19.304 18.796 0.863 0.711
ASME B18.21.1 #10 (0.190) 5.181 4.953 15.494 14.732 0.863 0.711
17.526 17.018 1.016 0.812
19.304 18.796 1.016 0.812
22.86 22.352 1.016 0.812
ASME B18.21.1 #12 (0.216) 5.867 5.613 17.526 17.018 1.016 0.812
19.304 18.415 1.016 0.812
22.86 22.352 1.016 0.812
25.019 24.511 1.143 0.939
ASME B18.21.1 1/4 (0.250) 6.781 6.502 19.304 18.415 1.016 0.812
22.86 22.352 1.016 0.812
25.019 24.511 1.143 0.939
27.178 26.543 1.143 0.939
ASME B18.21.1 5/16 (0.312) 8.432 8.128 22.86 21.971 1.016 0.812
25.019 24.511 1.143 0.939
27.178 26.543 1.27 1.066
29.337 28.702 1.27 1.066
ASME B18.21.1 3/8 (0.375) 10.109 9.753 25.019 24.511 1.143 0.939
27.178 26.543 1.27 1.066
32.004 30.988 1.27 1.066
ASME B18.21.1 7/16 (0.438) 11.785 11.379 27.178 26.543 1.27 1.066
29.337 28.702 1.27 1.066
33.401 32.766 1.397 1.193
32.004 30.988 1.397 1.193
ASME B18.21.1 1/2 (0.500) 13.462 13.004 33.401 32.766 1.397 1.193
35.814 35.052 1.524 1.32
41.148 40.386 1.701 1.498
ASME B18.21.1 9/16 (0.562) 15.138 14.63 33.401 32.766 1.397 1.193
35.814 35.052 1.524 1.32
41.148 40.386 1.701 1.498
46.482 45.643 1.701 1.498
ASME B18.21.1 5/8 (0.625) 16.84 16.256 35.814 35.052 1.524 1.32
41.148 40.386 1.701 1.498
50.165 49.149 1.701 1.498

ASME B18.21.1 Internal External Tooth Lock Washers Dimensions (Inch)

Nominal Size Inside Diameter, A Outside Diameter, B Thickness, C
Max. Min. Max. Min. Max. Min.
ASME B18.21.1 #4 (0.112) 0.123 0.115 0.475 0.46 0.021 0.016
0.51 0.495 0.021 0.017
0.61 0.58 0.021 0.017
ASME B18.21.1 #6 (0.138) 0.15 0.141 0.51 0.495 0.028 0.023
0.61 0.58 0.028 0.023
0.69 0.67 0.028 0.023
ASME B18.21.1 #8 (0.164) 0.176 0.168 0.61 0.58 0.034 0.028
0.69 0.67 0.034 0.028
0.76 0.74 0.034 0.028
ASME B18.21.1 #10 (0.190) 0.204 0.195 0.61 0.58 0.034 0.028
0.69 0.67 0.04 0.032
0.76 0.74 0.04 0.032
0.9 0.88 0.04 0.032
ASME B18.21.1 #12 (0.216) 0.231 0.221 0.69 0.67 0.04 0.032
0.76 0.725 0.04 0.032
0.9 0.88 0.04 0.032
0.985 0.965 0.045 0.037
ASME B18.21.1 1/4 (0.250) 0.267 0.256 0.76 0.725 0.04 0.032
0.9 0.88 0.04 0.032
0.985 0.965 0.045 0.037
1.07 1.045 0.045 0.037
ASME B18.21.1 5/16 (0.312) 0.332 0.32 0.9 0.865 0.04 0.032
0.985 0.965 0.045 0.037
1.07 1.045 0.05 0.042
1.155 1.13 0.05 0.042
ASME B18.21.1 3/8 (0.375) 0.398 0.384 0.985 0.965 0.045 0.037
1.07 1.045 0.05 0.042
1.26 1.22 0.05 0.042
ASME B18.21.1 7/16 (0.438) 0.464 0.448 1.07 1.045 0.05 0.042
1.155 1.13 0.05 0.042
1.315 1.29 0.055 0.047
1.26 1.22 0.055 0.047
ASME B18.21.1 1/2 (0.500) 0.53 0.512 1.315 1.29 0.055 0.047
1.41 1.38 0.06 0.052
1.62 1.59 0.067 0.059
ASME B18.21.1 9/16 (0.562) 0.596 0.576 1.315 1.29 0.055 0.047
1.41 1.38 0.06 0.052
1.62 1.59 0.067 0.059
1.83 1.797 0.067 0.059
ASME B18.21.1 5/8 (0.625) 0.663 0.64 1.41 1.38 0.06 0.052
1.62 1.59 0.067 0.059
1.975 1.935 0.067 0.059

ASME Material Specifications

ASTM A693 Washers
ASTM F436/F436M Washers
ASTM F959/959M Direct Tension Squirter DTI Washers
ASTM F2437/2437M Direct Tension Squirter DTI Washers
ASTM F844 Washers
ISO 898-3 Washers
ASTM A36 Washers
ASTM A240 Washers, Spacer, Flange
ASTM B96 Washers
ASTM B127 Washers
ASTM B162 Washers
ASTM B168 Washers
ASTM B171 Washers
ASTM B265 Washers
ASTM B409 Washers
ASTM B424 Washers
ASTM B551 Washers
ASTM B708 Washers

EN Material Specifications

ISO Material Specifications