About Washers
More
Countersunk External-Tooth Lock Washers
The teeth on these washers firmly grip heads of 82° flat head countersunk screws to prevent joints from loosening under vibration.
Black-oxide steel washers are mildly corrosion resistant in dry environments.
Zinc-plated steel washers are corrosion resistant in wet environments.
400-series stainless steel washers have excellent wear resistance and may be mildly magnetic.
All washers meet ASME B18.21.1 dimensional standards. The zinc-plated steel washers also meet standards for material properties.
For technical drawings and 3-D models, click on a part number.
| For Screw Size  | ID | OD | Thick. | Countersink Angle | Hardness | Specifications Met | Pkg. Qty. | Pkg. | |
Black-Oxide Steel | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| No. 4 | 0.113" | 0.213" | 0.015"-0.019" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 00000 |
| No. 6 | 0.140" | 0.289" | 0.017"-0.021" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 00000 |
| No. 8 | 0.167" | 0.322" | 0.017"-0.021" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| No. 10 | 0.195" | 0.354" | 0.020"-0.025" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| No. 12 | 0.220" | 0.421" | 0.020"-0.025" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| 1/4" | 0.255" | 0.454" | 0.020"-0.025" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| 5/16" | 0.318" | 0.599" | 0.023"-0.028" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| 3/8" | 0.383" | 0.765" | 0.028"-0.034" | 82° | Rockwell C40 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| 1/2" | 0.512" | 0.976" | 0.037"-0.045" | 82° | Rockwell C40 | ASME B18.21.1 | 10 | 000000000 | 00000 |
Zinc-Plated Steel | |||||||||
| No. 4 | 0.113" | 0.213" | 0.015"-0.019" | 82° | Rockwell C44 | ASME B18.21.1 | 50 | 000000000 | 00000 |
| No. 6 | 0.140" | 0.289" | 0.017"-0.021" | 82° | Rockwell C44 | ASME B18.21.1 | 100 | 000000000 | 00000 |
| No. 8 | 0.167" | 0.322" | 0.017"-0.021" | 82° | Rockwell C44 | ASME B18.21.1 | 100 | 000000000 | 00000 |
| No. 10 | 0.195" | 0.354" | 0.020"-0.025" | 82° | Rockwell C44 | ASME B18.21.1 | 50 | 000000000 | 00000 |
| No. 12 | 0.220" | 0.421" | 0.020"-0.025" | 82° | Rockwell C44 | ASME B18.21.1 | 100 | 000000000 | 00000 |
| 1/4" | 0.255" | 0.458" | 0.022" | 82° | Rockwell C40 | ASME B18.21.1 | 100 | 000000000 | 00000 |
| 5/16" | 0.318" | 0.599" | 0.023"-0.028" | 82° | Rockwell C44 | ASME B18.21.1 | 100 | 000000000 | 00000 |
| 3/8" | 0.383" | 0.765" | 0.028"-0.034" | 82° | Rockwell C44 | ASME B18.21.1 | 25 | 000000000 | 00000 |
| 1/2" | 0.512" | 0.976" | 0.037"-0.045" | 82° | Rockwell C44 | ASME B18.21.1 | 10 | 000000000 | 0000 |
400 Series Stainless Steel | |||||||||
| No. 6 | 0.140" | 0.289" | 0.017"-0.021" | 82° | Rockwell C34 | ASME B18.21.1 | 100 | 000000000 | 0000 |
| No. 8 | 0.167" | 0.322" | 0.017"-0.021" | 82° | Rockwell C34 | ASME B18.21.1 | 100 | 000000000 | 00000 |
| No. 10 | 0.195" | 0.354" | 0.020"-0.025" | 82° | Rockwell C34 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| No. 12 | 0.220" | 0.421" | 0.020"-0.025" | 82° | Rockwell C34 | ASME B18.21.1 | 50 | 000000000 | 00000 |
| 1/4" | 0.255" | 0.454" | 0.020"-0.025" | 82° | Rockwell C34 | ASME B18.21.1 | 25 | 000000000 | 0000 |
| 5/16" | 0.318" | 0.599" | 0.023"-0.028" | 82° | Rockwell C34 | ASME B18.21.1 | 25 | 000000000 | 0000 |