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Specifications Met Specifications Met |
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Flange Diameter Flange Diameter |
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Flange Thickness Flange Thickness |
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DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense AcquisitionRegulations Supplement) |
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RoHS (Restriction of Hazardous Substances) RoHS (Restriction ofHazardous Substances) |
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REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration,Evaluation, Authorization and Restriction of Chemicals) |
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Distorted Thread Type Distorted Thread Type |
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About Nuts, Materials, and Finishes
More
Mil. Spec. Low-Strength Steel Distorted-Thread Flange Locknuts

Choose these flange locknuts for their adherence to strict military standards for material and construction. They have an irregularly-shaped thread that grips the bolt for a stronger hold than nylon-insert flange locknuts. A flange that distributes pressure where the nut meets the material surface, eliminating the need for a separate washer. They're not reusable. A cadmium yellow-chromate plating provides corrosion resistance in wet environments. Height includes the flange.
Locknuts with lubricant keep screws from binding to the locknuts while you tighten them. They’re often used with screws made from soft metals, such as aluminum, which are more likely to bind to the locknuts than harder materials such as steel.
For technical drawings and 3-D models, click on a part number.
Flange | Locknuts | Locknuts with Lubricant | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Thread Size | Wd. | Ht. | Dia. | Thick. | Pkg. Qty. | Specifications Met | Pkg. | Specifications Met | Pkg. | ||
Cadmium Yellow-Chromate Plated Steel | |||||||||||
2-56 | 1/8" | 3/32" | 0.167" | 0.01" | 5 | MS21042-02 | 000000000 | 00000 | MS21042L-02 | 000000000 | 000000 |
4-40 | 5/32" | 1/8" | 0.206" | 0.03" | 5 | MS21042-04 | 000000000 | 0000 | MS21042L-04 | 000000000 | 0000 |
6-32 | 3/16" | 9/64" | 0.244" | 0.03" | 5 | MS21042-06 | 000000000 | 0000 | MS21042L-06 | 000000000 | 0000 |
8-32 | 7/32" | 3/16" | 0.29" | 0.03" | 5 | MS21042-08 | 000000000 | 0000 | MS21042L-08 | 000000000 | 0000 |
10-32 | 1/4" | 3/16" | 0.33" | 0.03" | 5 | MS21042-3 | 000000000 | 0000 | MS21042L-3 | 000000000 | 0000 |
1/4"-28 | 5/16" | 7/32" | 0.42" | 0.04" | 5 | MS21042-4 | 000000000 | 0000 | MS21042L-4 | 000000000 | 0000 |
5/16"-24 | 3/8" | 17/64" | 0.52" | 0.04" | 1 | MS21042-5 | 000000000 | 0000 | MS21042L-5 | 000000000 | 0000 |
3/8"-24 | 7/16" | 9/32" | 0.62" | 0.04" | 1 | MS21042-6 | 000000000 | 0000 | MS21042L-6 | 000000000 | 0000 |
Metric High-Strength Steel Distorted-Thread Flange Locknuts—Class 10

Grip metric bolts more securely than nylon-insert flange locknuts—the irregularly shaped threads on these locknuts hold extra tight. They resist vibration and sudden shocks, even after multiple uses. Thanks to their flange, these nuts distribute pressure across a greater area than standard nuts, so you don’t need to add a washer. However, they may not fit in tight spaces. Made of high-strength, Class 10 steel, these nuts are about 25% stronger than medium-strength steel flange nuts. Their strength is comparable to Class 10.9 bolts. A zinc plating protects the steel under it from rust, extending the life of the nut.
These flange nuts meet DIN and ISO dimensional standards that confirm their compatibility with other parts and tools. ISO 7044 is functionally equivalent to DIN 1664 (formerly DIN 6927).
For technical drawings and 3-D models, click on a part number.
Thread | Flange | ||||||||
---|---|---|---|---|---|---|---|---|---|
Size | Pitch, mm | Wd., mm | Ht., mm | Dia., mm | Thick., mm | Specifications Met | Pkg. Qty. | Pkg. | |
Zinc-Plated Steel—Class 10 | |||||||||
M6 | 1 | 10 | 7.3 | 14.2 | 1.1 | DIN 1664, DIN 6927, ISO 7044 | 50 | 0000000 | 000000 |
M8 | 1.25 | 13 | 9.4 | 17.9 | 1.2 | DIN 1664, DIN 6927, ISO 7044 | 25 | 0000000 | 00000 |
M10 | 1.5 | 15 | 11.4 | 21.8 | 1.5 | DIN 1664, DIN 6927, ISO 7044 | 10 | 0000000 | 0000 |
M12 | 1.75 | 18 | 13.8 | 26 | 1.8 | DIN 1664, DIN 6927, ISO 7044 | 10 | 0000000 | 00000 |
M14 | 2 | 21 | 15.9 | 29.9 | 2.1 | DIN 1664, DIN 6927, ISO 7044 | 5 | 0000000 | 00000 |
M16 | 2 | 24 | 18.3 | 34.5 | 2.4 | DIN 1664, DIN 6927, ISO 7044 | 1 | 0000000 | 0000 |
M20 | 2.5 | 30 | 22.4 | 42.8 | 3 | DIN 1664, DIN 6927, ISO 7044 | 1 | 0000000 | 0000 |
High-Strength Steel Distorted-Thread Flange Locknuts

An irregularly-shaped thread grips the bolt for a stronger hold than nylon-insert flange locknuts. They have a flange that distributes pressure where the nut meets the material surface, eliminating the need for a separate washer. Grade G locknuts are comparable in strength to Grade 8 bolts. Height includes the flange.
Black-oxide steel locknuts are mildly corrosion resistant.
Zinc yellow-chromate plated steel locknuts resist corrosion in wet environments.
For technical drawings and 3-D models, click on a part number.
Flange | |||||||
---|---|---|---|---|---|---|---|
Thread Size | Wd. | Ht. | Dia. | Thick. | Pkg. Qty. | Pkg. | |
Black-Oxide Steel—Grade G | |||||||
1/4"-20 | 7/16" | 19/64" | 9/16" | 0.04" | 50 | 000000000 | 000000 |
1/4"-28 | 7/16" | 19/64" | 9/16" | 0.04" | 50 | 000000000 | 00000 |
5/16"-18 | 1/2" | 23/64" | 11/16" | 0.05" | 25 | 000000000 | 00000 |
5/16"-24 | 1/2" | 23/64" | 11/16" | 0.05" | 25 | 000000000 | 00000 |
3/8"-16 | 9/16" | 27/64" | 13/16" | 0.06" | 25 | 000000000 | 00000 |
3/8"-24 | 9/16" | 27/64" | 13/16" | 0.06" | 25 | 000000000 | 00000 |
1/2"-13 | 3/4" | 9/16" | 1 1/16" | 0.08" | 10 | 000000000 | 00000 |
1/2"-20 | 3/4" | 9/16" | 1 1/16" | 0.08" | 10 | 000000000 | 00000 |
5/8"-11 | 15/16" | 11/16" | 1 21/64" | 0.1" | 10 | 000000000 | 00000 |
5/8"-18 | 15/16" | 11/16" | 1 21/64" | 0.1" | 10 | 000000000 | 00000 |
3/4"-10 | 1 1/8" | 13/16" | 1 37/64" | 0.11" | 5 | 000000000 | 00000 |
Black-Phosphate Steel—Grade G | |||||||
1/4"-20 | 7/16" | 19/64" | 9/16" | 0.04" | 100 | 000000000 | 0000 |
1/4"-28 | 7/16" | 19/64" | 9/16" | 0.04" | 100 | 000000000 | 0000 |
5/16"-18 | 1/2" | 23/64" | 11/16" | 0.05" | 100 | 000000000 | 00000 |
5/16"-24 | 1/2" | 23/64" | 11/16" | 0.05" | 100 | 000000000 | 00000 |
3/8"-16 | 9/16" | 27/64" | 13/16" | 0.06" | 50 | 000000000 | 00000 |
3/8"-24 | 9/16" | 27/64" | 13/16" | 0.06" | 25 | 000000000 | 00000 |
1/2"-13 | 3/4" | 9/16" | 1 1/16" | 0.08" | 25 | 000000000 | 00000 |
1/2"-20 | 3/4" | 9/16" | 1 1/16" | 0.08" | 25 | 000000000 | 0000 |
5/8"-11 | 15/16" | 11/16" | 1 21/64" | 0.1" | 10 | 000000000 | 00000 |
5/8"-18 | 15/16" | 11/16" | 1 21/64" | 0.1" | 10 | 000000000 | 0000 |
3/4"-10 | 1 1/8" | 53/64" | 1 37/64" | 0.11" | 10 | 000000000 | 00000 |
3/4"-16 | 1 1/8" | 53/64" | 1 37/64" | 0.11" | 10 | 000000000 | 0000 |
7/8"-9 | 1 5/16" | 51/64" | 1 3/4" | 0.12" | 5 | 000000000 | 00000 |
7/8"-14 | 1 5/16" | 51/64" | 1 3/4" | 0.12" | 5 | 000000000 | 00000 |
1"-8 | 1 1/2" | 57/64" | 2 1/16" | 0.13" | 5 | 000000000 | 00000 |
1"-14 | 1 1/2" | 57/64" | 2 1/16" | 0.13" | 5 | 000000000 | 00000 |
Zinc Yellow-Chromate Plated Steel—Grade G | |||||||
1/4"-20 | 7/16" | 19/64" | 9/16" | 0.04" | 50 | 000000000 | 00000 |
1/4"-28 | 7/16" | 19/64" | 9/16" | 0.04" | 50 | 000000000 | 00000 |
5/16"-18 | 1/2" | 23/64" | 11/16" | 0.05" | 25 | 000000000 | 00000 |
5/16"-24 | 1/2" | 23/64" | 11/16" | 0.05" | 25 | 000000000 | 00000 |
3/8"-16 | 9/16" | 27/64" | 13/16" | 0.06" | 25 | 000000000 | 00000 |
3/8"-24 | 9/16" | 27/64" | 13/16" | 0.06" | 25 | 000000000 | 00000 |
1/2"-13 | 3/4" | 9/16" | 1 1/16" | 0.08" | 10 | 000000000 | 0000 |
1/2"-20 | 3/4" | 9/16" | 1 1/16" | 0.08" | 10 | 000000000 | 00000 |
5/8"-11 | 15/16" | 11/16" | 1 21/64" | 0.1" | 10 | 000000000 | 00000 |
5/8"-18 | 15/16" | 11/16" | 1 21/64" | 0.1" | 10 | 000000000 | 00000 |
3/4"-10 | 1 1/8" | 13/16" | 1 37/64" | 0.11" | 5 | 000000000 | 00000 |
Stainless Steel Distorted-Thread Flange Locknuts

These flange locknuts have excellent resistance to chemicals and salt water. They have an irregularly shaped thread that grips the bolt for a stronger hold than nylon-insert flange locknuts. A flange distributes pressure where the nut meets the material surface, eliminating the need for a separate washer. These nuts may be mildly magnetic. Height includes the flange.
A286 stainless steel nuts cannot be reused. Those with lubricant thread onto bolts smoothly.
18-8 stainless steel nuts have a serrated flange—the serrations grip the material surface for mild vibration resistance. These nuts can be used multiple times.
For technical drawings and 3-D models, click on a part number.
Flange | ||||||||
---|---|---|---|---|---|---|---|---|
Thread Size | Wd. | Ht. | Dia. | Thick. | Specifications Met | Pkg. Qty. | Pkg. | |
Silver-Plated A286 Stainless Steel | ||||||||
4-40 | 5/32" | 1/8" | 0.206" | 0.03" | MS21043-04 | 5 | 000000000 | 000000 |
6-32 | 3/16" | 9/64" | 0.244" | 0.03" | MS21043-06 | 5 | 000000000 | 0000 |
8-32 | 7/32" | 3/16" | 0.29" | 0.03" | MS21043-08 | 5 | 000000000 | 00000 |
10-32 | 1/4" | 3/16" | 0.33" | 0.03" | MS21043-3 | 5 | 000000000 | 0000 |
1/4"-28 | 5/16" | 7/32" | 0.42" | 0.04" | MS21043-4 | 5 | 000000000 | 0000 |
5/16"-24 | 3/8" | 17/64" | 0.52" | 0.04" | MS21043-5 | 1 | 000000000 | 0000 |
3/8"-24 | 7/16" | 9/32" | 0.62" | 0.04" | MS21043-6 | 1 | 000000000 | 0000 |
A286 Stainless Steel with Lubricant | ||||||||
2-56 | 1/8" | 3/32" | 0.167" | 0.01" | NAS1291C02M | 5 | 000000000 | 00000 |
4-40 | 5/32" | 1/8" | 0.206" | 0.01" | NAS1291C04M | 1 | 000000000 | 0000 |
6-32 | 3/16" | 9/64" | 0.244" | 0.01" | NAS1291C06M | 1 | 000000000 | 0000 |
8-32 | 7/32" | 3/16" | 0.29" | 0.02" | NAS1291C08M | 1 | 000000000 | 0000 |
10-32 | 1/4" | 3/16" | 0.33" | 0.02" | NAS1291C3M | 1 | 000000000 | 0000 |
1/4"-28 | 5/16" | 7/32" | 0.42" | 0.02" | NAS1291C4M | 1 | 000000000 | 0000 |
5/16"-24 | 3/8" | 17/64" | 0.52" | 0.03" | NAS1291C5M | 1 | 000000000 | 0000 |
3/8"-24 | 7/16" | 9/32" | 0.62" | 0.03" | NAS1291C6M | 1 | 000000000 | 00000 |
7/16"-20 | 1/2" | 21/64" | 0.708" | 0.04" | NAS1291C7M | 1 | 000000000 | 00000 |
1/2"-20 | 9/16" | 13/32" | 0.814" | 0.04" | NAS1291C8M | 1 | 000000000 | 00000 |
18-8 Stainless Steel | ||||||||
1/4"-20 | 7/16" | 15/64" | 0.594" | 0.04" | __ | 10 | 000000000 | 0000 |
5/16"-18 | 1/2" | 9/32" | 0.68" | 0.04" | __ | 10 | 000000000 | 0000 |
3/8"-16 | 9/16" | 11/32" | 0.75" | 0.04" | __ | 10 | 000000000 | 0000 |
1/2"-13 | 3/4" | 29/64" | 1.031" | 0.04" | __ | 5 | 000000000 | 0000 |