Standard ASME B18.21.1 TABLE 3
Helical spring-lock washers extra-duty series

Dimensions in inches: source ASME B18.21.1 -2009-Table 3 Extra-duty series | |||||||
Nominal washer size | A max | A min | B max | T mean section thickness (t1+t)/2 | W min | ||
No.2 (0.086) | 0.094 | 0.088 | 0.208 | 0.027 | 0.053 | ||
No.3 (0.099) | 0.107 | 0.101 | 0.239 | 0.034 | 0.062 | ||
No.4 (0.112) | 0.120 | 0.114 | 0.253 | 0.034 | 0.062 | ||
No.5 (0.125) | 0.133 | 0.127 | 0.300 | 0.045 | 0.079 | ||
No.6 (0.138) | 0.148 | 0.141 | 0.314 | 0.045 | 0.079 | ||
No.8 (0.164) | |||||||
No.10 (0.190) | |||||||
No.12 (0.216) | |||||||
1/4 - (0.250) | |||||||
5/16 - (0.3125) | |||||||
3/8 - (0.375) | |||||||
7/16 -(0.4375) | |||||||
1/2 - (0.5) | |||||||
9/16 - (0.5625) | |||||||
5/8 - (0.625) | |||||||
11/16 - (0.6875) | |||||||
3/4 - (0.75) | |||||||
13/16 -(0.8125) | |||||||
7/8 - (0.875) | |||||||
15/16 (0.9375) | |||||||
1 - (1) | |||||||
1-1/16 (1.0625) | |||||||
1-1/8 (1.125) | |||||||
1-3/16 (1.875) | |||||||
1- 1/4 (1.25) | |||||||
1 - 5/16 (1.3125) | |||||||
1 - 3/8 (1.375) | |||||||
1 - 7/16 (1.4375) | |||||||
1 - 1/2 (1.5) | |||||||
1 - 5/8 (1.625) | |||||||
1 - 3/4 (1.75) | |||||||
1 - 7/8 (1.875) | |||||||
2 (2) |