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Split Lock Washers

As a screw is tightened, these washers flatten to add tension to the joint, counteracting fatigue around the joint from small amounts of vibration. This makes them a common choice to prevent fasteners from loosening. However, they resist the least amount of vibration compared to other locking washers.
These washers are compatible with fasteners that have right-hand threads to prevent clockwise rotation. The uneven split ends bite into fasteners for a tight grip, but they won’t work with hardened surfaces. These washers hold better than curved or wave washers. They are not reusable after tightening.
Bronze washers are corrosion resistant in wet environments, nonmagnetic, and electrically conductive.
Washers that meet ASME B18.21.1 adhere to strict dimensional standards.
For technical drawings and 3-D models, click on a part number.
For Screw Size | ID | OD | Thick. | Hardness | Specifications Met | Pkg. Qty. | Pkg. | |
Bronze | ||||||||
---|---|---|---|---|---|---|---|---|
No. 2 | 0.094" | 0.172" | 0.020" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 00000 |
No. 3 | 0.107" | 0.195" | 0.025" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 4 | 0.120" | 0.209" | 0.025" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 4 | 0.120" | 0.209" | 0.025" | Rockwell B90 | ASME B18.21.1 | 1,000 | 000000000 | 00000 |
No. 6 | 0.148" | 0.250" | 0.031" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 6 | 0.148" | 0.250" | 0.031" | Rockwell B90 | ASME B18.21.1 | 1,000 | 000000000 | 00000 |
No. 8 | 0.174" | 0.293" | 0.040" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 8 | 0.174" | 0.293" | 0.040" | Rockwell B90 | ASME B18.21.1 | 1,000 | 000000000 | 00000 |
No. 10 | 0.200" | 0.334" | 0.047" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 12 | 0.227" | 0.377" | 0.056" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 0000 |
1/4" | 0.260" | 0.487" | 0.062" | Rockwell B90 | ASME B18.21.1 | 100 | 000000000 | 00000 |
5/16" | 0.322" | 0.583" | 0.078" | Rockwell B90 | ASME B18.21.1 | 50 | 000000000 | 00000 |
3/8" | 0.385" | 0.680" | 0.094" | Rockwell B90 | ASME B18.21.1 | 25 | 000000000 | 00000 |
7/16" | 0.450" | 0.776" | 0.109" | Rockwell B90 | ASME B18.21.1 | 10 | 000000000 | 0000 |
1/2" | 0.512" | 0.869" | 0.125" | Rockwell B90 | ASME B18.21.1 | 10 | 000000000 | 0000 |
5/8" | 0.641" | 1.073" | 0.156" | Rockwell B90 | ASME B18.21.1 | 5 | 000000000 | 0000 |
3/4" | 0.766" | 1.265" | 0.188" | Rockwell B90 | ASME B18.21.1 | 5 | 000000000 | 00000 |
1" | 1.024" | 1.656" | 0.250" | Rockwell B90 | ASME B18.21.1 | 5 | 000000000 | 00000 |
Internal-Tooth Lock Washers

Internal teeth dig into the screw head while the smooth outside edge won't snag objects. These washers provide greater vibration resistance than split lock washers. Use with fasteners that have small heads, such as fillister and cheese head screws.
Bronze washers are corrosion resistant in wet environments, nonmagnetic, and electrically conductive.
Washers that meet ASME B18.21.1 adhere to strict dimensional standards.
For technical drawings and 3-D models, click on a part number.
For Screw Size | ID | OD | Thickness | Hardness | Specifications Met | Pkg. Qty. | Pkg. | |
Bronze | ||||||||
---|---|---|---|---|---|---|---|---|
No. 2 | 0.089" | 0.200" | 0.010"-0.016" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 00000 |
No. 3 | 0.109" | 0.232" | 0.010"-0.016" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 4 | 0.115" | 0.270" | 0.012"-0.018" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 5 | 0.136" | 0.280" | 0.014"-0.018" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 6 | 0.141" | 0.295" | 0.016"-0.022" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 8 | 0.168" | 0.340" | 0.018"-0.023" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 10 | 0.195" | 0.381" | 0.018"-0.024" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 12 | 0.231" | 0.410" | 0.020"-0.027" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 00000 |
1/4" | 0.256" | 0.478" | 0.023"-0.028" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 00000 |
5/16" | 0.320" | 0.610" | 0.028"-0.034" | Rockwell B60 | ASME B18.21.1 | 50 | 000000000 | 0000 |
3/8" | 0.384" | 0.692" | 0.032"-0.040" | Rockwell B60 | ASME B18.21.1 | 50 | 000000000 | 00000 |
7/16" | 0.448" | 0.789" | 0.032"-0.040" | Rockwell B60 | ASME B18.21.1 | 25 | 000000000 | 0000 |
1/2" | 0.512" | 0.900" | 0.037"-0.045" | Rockwell B60 | ASME B18.21.1 | 25 | 000000000 | 00000 |
5/8" | 0.640" | 1.071" | 0.042"-0.050" | Rockwell B60 | ASME B18.21.1 | 5 | 000000000 | 0000 |
3/4" | 0.795" | 1.245" | 0.047"-0.055" | Rockwell B60 | ASME B18.21.1 | 5 | 000000000 | 0000 |
Mil. Spec. Internal-Tooth Lock Washers

Choose these washers for their adherence to strict military standards for material and construction. Internal teeth dig into the screw head while the smooth outside edge won't snag objects. These washers provide greater vibration resistance than split lock washers. Use with fasteners that have small heads, such as fillister and cheese head screws.
Bronze washers are corrosion resistant in wet environments, nonmagnetic, and electrically conductive.
For technical drawings and 3-D models, click on a part number.
For Screw Size | ID | OD | Thick. | Hardness | Specifications Met | Pkg. Qty. | Pkg. | |
Bronze | ||||||||
---|---|---|---|---|---|---|---|---|
MS-35333/NASM 35333 | ||||||||
No. 2 | 0.089" | 0.200" | 0.010"-0.015" | Rockwell B90 | ASME B18.21.1; MS35333-103; NASM35333 | 25 | 000000000 | 00000 |
No. 4 | 0.115" | 0.270" | 0.015"-0.019" | Rockwell B90 | ASME B18.21.1; MS35333-104; NASM35333 | 25 | 000000000 | 0000 |
No. 6 | 0.141" | 0.295" | 0.017"-0.021" | Rockwell B90 | ASME B18.21.1; MS35333-105; NASM35333 | 25 | 000000000 | 00000 |
No. 8 | 0.168" | 0.340" | 0.018"-0.023" | Rockwell B90 | ASME B18.21.1; MS35333-106; NASM35333 | 25 | 000000000 | 00000 |
No. 10 | 0.195" | 0.381" | 0.020"-0.025" | Rockwell B90 | ASME B18.21.1; MS35333-107; NASM35333 | 25 | 000000000 | 00000 |
1/4" | 0.256" | 0.478" | 0.023"-0.028" | Rockwell B90 | ASME B18.21.1; MS35333-108; NASM35333 | 25 | 000000000 | 00000 |
5/16" | 0.332" | 0.610" | 0.028"-0.034" | Rockwell B90 | ASME B18.21.1; MS35333-109; NASM35333 | 10 | 000000000 | 0000 |
3/8" | 0.384" | 0.692" | 0.032"-0.040" | Rockwell B90 | ASME B18.21.1; MS35333-110; NASM35333 | 10 | 000000000 | 0000 |
1/2" | 0.512" | 0.900" | 0.037"-0.045" | Rockwell B90 | ASME B18.21.1; MS35333-113; NASM35333 | 5 | 000000000 | 0000 |
External-Tooth Lock Washers

Teeth on the outside edge of the washer bite into the screw head and joint for a tight grip. Use with fasteners that have heads large enough to make contact with the teeth, such as pan, button, and binding head screws.
Bronze washers are corrosion resistant in wet environments, nonmagnetic, and electrically conductive.
Washers that meet ASME B18.21.1 adhere to strict dimensional standards.
For technical drawings and 3-D models, click on a part number.
For Screw Size | ID | OD | Thick. | Hardness | Specifications Met | Pkg. Qty. | Pkg. | |
Bronze | ||||||||
---|---|---|---|---|---|---|---|---|
No. 3 | 0.102" | 0.235" | 0.010"-0.016" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 00000 |
No. 4 | 0.115" | 0.260" | 0.012"-0.018" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 6 | 0.141" | 0.320" | 0.016"-0.022" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 8 | 0.168" | 0.381" | 0.018"-0.023" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 10 | 0.195" | 0.410" | 0.018"-0.024" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
No. 12 | 0.221" | 0.475" | 0.020"-0.027" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 0000 |
1/4" | 0.256" | 0.510" | 0.023"-0.028" | Rockwell B60 | ASME B18.21.1 | 100 | 000000000 | 00000 |
5/16" | 0.320" | 0.610" | 0.028"-0.034" | Rockwell B60 | ASME B18.21.1 | 50 | 000000000 | 0000 |
3/8" | 0.384" | 0.694" | 0.032"-0.040" | Rockwell B60 | ASME B18.21.1 | 25 | 000000000 | 0000 |
7/16" | 0.448" | 0.760" | 0.032"-0.040" | Rockwell B60 | ASME B18.21.1 | 25 | 000000000 | 0000 |
1/2" | 0.513" | 0.900" | 0.037"-0.045" | Rockwell B60 | ASME B18.21.1 | 25 | 000000000 | 00000 |
5/8" | 0.641" | 1.070" | 0.042"-0.050" | Rockwell B60 | ASME B18.21.1 | 10 | 000000000 | 00000 |
3/4" | 0.768" | 1.260" | 0.047"-0.055" | Rockwell B60 | ASME B18.21.1 | 5 | 000000000 | 0000 |
Mil. Spec. External-Tooth Lock Washers

Choose these washers for their adherence to strict military standards for material and construction. Teeth on the outside edge of the washer bite into the screw head and joint for a tight grip. Use with fasteners that have heads large enough to make contact with the teeth, such as pan, button, and binding head screws.
Bronze washers are corrosion resistant in wet environments, nonmagnetic, and electrically conductive.
For technical drawings and 3-D models, click on a part number.
For Screw Size | ID | OD | Thick. | Hardness | Specifications Met | Military Specifications Met | Pkg. Qty. | Pkg. | |
Bronze | |||||||||
---|---|---|---|---|---|---|---|---|---|
MS-35335/NASM 35335 | |||||||||
No. 10 | 0.195" | 0.410" | 0.020"-0.025" | Not Rated | ASME B18.21.1; MS35335-88 | MS35335 | 25 | 000000000 | 00000 |
1/4" | 0.256" | 0.510" | 0.023"-0.028" | Not Rated | ASME B18.21.1; MS35335-89 | MS35335 | 10 | 000000000 | 0000 |
5/16" | 0.320" | 0.610" | 0.028"-0.034" | Not Rated | ASME B18.21.1; MS35335-90 | MS35335 | 10 | 000000000 | 0000 |
3/8" | 0.384" | 0.694" | 0.032"-0.040" | Not Rated | ASME B18.21.1; MS35335-91 | MS35335 | 10 | 000000000 | 0000 |
1/2" | 0.513" | 0.900" | 0.037"-0.045" | Not Rated | ASME B18.21.1; MS35335-93 | MS35335 | 10 | 000000000 | 0000 |