Black Oxide SAE flat washers to go with all your black hardware/strong>
1/2" SAE - 0.54 ID, 1.1 OD
1/2" USS - 0.577 ID, 1.39 OD
3/8" SAE - 0.42 ID, 0.81 OD
3/8" compression - 0.41 ID, 0.990 OD
5/16" SAE - 0.36 ID, 0.69 OD
5/16" USS - 0.385 ID, 0.875 OD
1/4" SAE - 0.29 ID, 0.62 OD
1/4" USS - 0.322 ID, 0.775 OD