Zinc = NK020----Z1
| Diameter | Width Across Flats | Width Across Corners | Thickness | Washer Diameter | |||
| Max | Min | Max | Min | Max | Min | ||
| #4 | 1/4 | .289 | .275 | .098 | .087 | .286 | .277 |
| #5 | 1/4 | .289 | .275 | .098 | .087 | .287 | .277 |
| #6 | 5/16 | .361 | .344 | .114 | .102 | .348 | .338 |
| #6SP | 1/4 | .289 | .275 | .098 | .087 | .287 | .277 |
| #8 | 11/32 | .397 | .378 | .130 | .117 | .381 | .370 |
| #8SP | 5/16 | .361 | .344 | .114 | .102 | .381 | .3780 |
| #10 | 3/8 | .433 | .413 | .130 | .117 | .406 | .395 |
| #12 | 7/16 | .505 | .482 | .161 | .148 | .506 | .494 |
| 1/4 | 7/16 | .505 | .482 | .193 | .178 | .506 | .494 |
| 5/16 | 1/2 | .577 | .557 | .273 | .258 | .592 | .579 |
| 3/8 | 9/16 | .650 | .628 | .385 | .365 | .665 | .651 |
| 1/2 | 3/4 | .866 | .840 | .437 | .425 | .898 | .878 |
Disclaimer: The dimensions listed are for reference only. Sizes not listed may be available off the shelf or can be manufactured to customer requirements.