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High-Strength Steel Center-Lock Distorted-Thread Locknuts—Grade 8



These locknuts have an irregularly shaped thread in the middle of the nut that grips the bolt for a stronger hold than nylon-insert locknuts. Also known as reversible locknuts, they can be threaded on from either end. They're about three times stronger than low-strength steel locknuts. The strength of the bolt should match the strength of the nut to prevent damaging threads. They're not reusable.
Black-oxide steel locknuts have a dark surface color and are mildly corrosion resistant in dry environments.
Zinc yellow-chromate plated steel locknuts resist corrosion in wet environments.
Zinc-flake-coated steel locknuts are more corrosion resistant in wet environments than zinc yellow-chromate plated steel locknuts.
For technical drawings and 3-D models, click on a part number.
| Thread Size | Wd. | Ht. | Pkg. Qty. | Pkg. | |
Black-Oxide Steel—Grade 8 | |||||
|---|---|---|---|---|---|
| 1/4"-20 | 7/16" | 7/32" | 10 | 000000000 | 00000 |
| 5/16"-18 | 1/2" | 17/64" | 10 | 000000000 | 0000 |
| 3/8"-16 | 9/16" | 21/64" | 10 | 000000000 | 0000 |
| 1/2"-13 | 3/4" | 7/16" | 5 | 000000000 | 00000 |
| 5/8"-11 | 15/16" | 35/64" | 1 | 000000000 | 0000 |
| 7/8"-9 | 1 5/16" | 3/4" | 1 | 000000000 | 00000 |
| 1"-8 | 1 1/2" | 55/64" | 1 | 000000000 | 00000 |
| 1"-14 | 1 1/2" | 55/64" | 1 | 000000000 | 00000 |
Zinc Yellow-Chromate Plated Steel—Grade 8 | |||||
| 1/4"-20 | 7/16" | 7/32" | 50 | 000000000 | 00000 |
| 1/4"-28 | 7/16" | 7/32" | 50 | 000000000 | 00000 |
| 5/16"-18 | 1/2" | 17/64" | 50 | 000000000 | 00000 |
| 5/16"-24 | 1/2" | 17/64" | 50 | 000000000 | 00000 |
| 3/8"-16 | 9/16" | 21/64" | 25 | 000000000 | 0000 |
| 3/8"-24 | 9/16" | 21/64" | 25 | 000000000 | 00000 |
| 7/16"-14 | 11/16" | 3/8" | 10 | 000000000 | 0000 |
| 7/16"-20 | 11/16" | 3/8" | 10 | 000000000 | 0000 |
| 1/2"-13 | 3/4" | 7/16" | 10 | 000000000 | 0000 |
| 1/2"-20 | 3/4" | 7/16" | 10 | 000000000 | 00000 |
| 9/16"-12 | 7/8" | 31/64" | 10 | 000000000 | 00000 |
| 5/8"-11 | 15/16" | 35/64" | 5 | 000000000 | 0000 |
| 5/8"-18 | 15/16" | 35/64" | 5 | 000000000 | 0000 |
| 3/4"-10 | 1 1/8" | 41/64" | 5 | 000000000 | 0000 |
| 3/4"-16 | 1 1/8" | 41/64" | 5 | 000000000 | 00000 |
| 7/8"-9 | 1 5/16" | 3/4" | 5 | 000000000 | 00000 |
| 1"-8 | 1 1/2" | 55/64" | 1 | 000000000 | 0000 |
| 1"-14 | 1 1/2" | 55/64" | 1 | 000000000 | 00000 |
Zinc-Flake-Coated Steel—Grade 8 | |||||
| 1/4"-20 | 7/16" | 7/32" | 10 | 000000000 | 0000 |
| 5/16"-18 | 1/2" | 17/64" | 10 | 000000000 | 00000 |
| 3/8"-16 | 9/16" | 21/64" | 5 | 000000000 | 0000 |
| 1/2"-13 | 3/4" | 7/16" | 5 | 000000000 | 00000 |
| 5/8"-11 | 15/16" | 35/64" | 1 | 000000000 | 0000 |
| 7/8"-9 | 1 5/16" | 3/4" | 1 | 000000000 | 00000 |
| 1"-8 | 1 1/2" | 55/64" | 1 | 000000000 | 00000 |
Left-Hand Threaded High-Strength Steel
Center-Lock Distorted-Thread Locknuts—Grade 8

These locknuts tighten when turned to the left. They have an irregularly shaped thread in the middle of the nut that grips the bolt for a stronger hold than nylon-insert locknuts. Also known as reversible locknuts, they can be threaded on from either end. They're about three times stronger than low-strength steel locknuts. The strength of the bolt should match the strength of the nut to prevent damaging threads. They're not reusable. A zinc plating provides corrosion resistance in wet environments.
For technical drawings and 3-D models, click on a part number.
Metric Medium-Strength Steel Center-Lock
Distorted-Thread Locknuts—Class 8

Strong enough for use with most machinery and equipment, these Class 8 metric locknuts have an irregularly shaped thread in the middle of the nut that grips bolts tighter than nylon-insert locknuts. Also known as reversible locknuts, they can be threaded on from either end. All are zinc-plated steel, so they won’t rust in wet and damp areas.
For technical drawings and 3-D models, click on a part number.
Thread | ||||||
|---|---|---|---|---|---|---|
| Size | Pitch, mm | Width, mm | Height, mm | Pkg. Qty. | Pkg. | |
Zinc-Plated Steel—Class 8 | ||||||
| M5 | 0.8 | 8 | 4 | 10 | 000000000 | 000000 |
| M6 | 1 | 10 | 5 | 10 | 000000000 | 00000 |
| M7 | 1 | 11 | 5.5 | 5 | 000000000 | 0000 |
| M8 | 1 | 13 | 6.5 | 10 | 000000000 | 00000 |
| M8 | 1.25 | 13 | 6.5 | 10 | 000000000 | 00000 |
| M10 | 1 | 17 | 8 | 5 | 000000000 | 0000 |
| M10 | 1.25 | 17 | 8 | 5 | 000000000 | 0000 |
| M10 | 1.5 | 17 | 8 | 10 | 000000000 | 00000 |
| M12 | 1.25 | 19 | 10 | 5 | 000000000 | 00000 |
| M12 | 1.5 | 19 | 10 | 5 | 000000000 | 00000 |
| M12 | 1.75 | 19 | 10 | 5 | 000000000 | 0000 |
| M14 | 1.5 | 22 | 11 | 5 | 000000000 | 00000 |
| M14 | 2 | 22 | 11 | 5 | 000000000 | 00000 |
| M16 | 1.5 | 24 | 13 | 5 | 000000000 | 00000 |
| M16 | 2 | 24 | 13 | 5 | 000000000 | 00000 |
| M22 | 1.5 | 32 | 18 | 1 | 000000000 | 00000 |
Low-Strength Steel Center-Lock Distorted-Thread Locknuts

An irregularly shaped thread in the middle of the nut grips the bolt for a stronger hold than nylon-insert locknuts. Also known as reversible locknuts, they can be threaded on from either end. The strength of the bolt should match the strength of the nut to prevent damaging threads. They're not reusable. Use them in light duty fastening applications, such as securing access panels. A zinc plating provides corrosion resistance in wet environments.
For technical drawings and 3-D models, click on a part number.
| Thread Size | Wd. | Ht. | Pkg. Qty. | Pkg. | |
Zinc-Plated Steel—Grade 2 | |||||
|---|---|---|---|---|---|
| 1/4"-20 | 7/16" | 7/32" | 100 | 000000000 | 00000 |
| 1/4"-28 | 7/16" | 7/32" | 100 | 000000000 | 00000 |
| 5/16"-18 | 1/2" | 17/64" | 100 | 000000000 | 0000 |
| 5/16"-24 | 1/2" | 17/64" | 100 | 000000000 | 0000 |
| 3/8"-16 | 9/16" | 21/64" | 100 | 000000000 | 00000 |
| 3/8"-24 | 9/16" | 21/64" | 100 | 000000000 | 00000 |
| 7/16"-14 | 11/16" | 3/8" | 50 | 000000000 | 00000 |
| 7/16"-20 | 11/16" | 3/8" | 50 | 000000000 | 00000 |
| 1/2"-13 | 3/4" | 7/16" | 50 | 000000000 | 00000 |
| 1/2"-20 | 3/4" | 7/16" | 50 | 000000000 | 00000 |
| 5/8"-11 | 15/16" | 35/64" | 25 | 000000000 | 00000 |
| 5/8"-18 | 15/16" | 35/64" | 25 | 000000000 | 00000 |
| 3/4"-10 | 1 1/8" | 41/64" | 10 | 000000000 | 00000 |
| 3/4"-16 | 1 1/8" | 41/64" | 10 | 000000000 | 00000 |
| 1"-14 | 1 1/2" | 55/64" | 5 | 000000000 | 00000 |
18-8 Stainless Steel Center-Lock Distorted-Thread Locknuts

These locknuts have good chemical resistance and may be mildly magnetic. They have an irregularly shaped thread in the middle of the nut that grips the bolt for a stronger hold than nylon-insert locknuts. Also known as reversible locknuts, they can be threaded on from either end. The strength of the bolt should match the strength of the nut to prevent damaging threads. They're not reusable.
For technical drawings and 3-D models, click on a part number.
| Thread Size | Wd. | Ht. | Pkg. Qty. | Pkg. | |
18-8 Stainless Steel | |||||
|---|---|---|---|---|---|
| 1/4"-20 | 7/16" | 7/32" | 50 | 000000000 | 00000 |
| 1/4"-28 | 7/16" | 7/32" | 50 | 000000000 | 00000 |
| 5/16"-18 | 1/2" | 17/64" | 50 | 000000000 | 00000 |
| 5/16"-24 | 1/2" | 17/64" | 25 | 000000000 | 0000 |
| 3/8"-16 | 9/16" | 21/64" | 25 | 000000000 | 0000 |
| 3/8"-24 | 9/16" | 21/64" | 25 | 000000000 | 0000 |
| 7/16"-14 | 11/16" | 3/8" | 10 | 000000000 | 0000 |
| 7/16"-20 | 11/16" | 3/8" | 10 | 000000000 | 0000 |
| 1/2"-13 | 3/4" | 7/16" | 10 | 000000000 | 0000 |
| 1/2"-20 | 3/4" | 7/16" | 10 | 000000000 | 0000 |
| 5/8"-11 | 15/16" | 35/64" | 5 | 000000000 | 0000 |
| 5/8"-18 | 15/16" | 35/64" | 5 | 000000000 | 00000 |
| 3/4"-10 | 1 1/8" | 41/64" | 5 | 000000000 | 00000 |
| 3/4"-16 | 1 1/8" | 41/64" | 1 | 000000000 | 0000 |
| 7/8"-9 | 1 5/16" | 3/4" | 1 | 000000000 | 0000 |
| 1"-8 | 1 1/2" | 55/64" | 1 | 000000000 | 0000 |
| 1"-14 | 1 1/2" | 55/64" | 1 | 000000000 | 0000 |
Super-Corrosion-Resistant 316 Stainless
Steel Center-Lock Distorted-Thread Locknuts

These locknuts have excellent resistance to chemicals and salt water. They have an irregularly shaped thread in the middle of the nut that grips the bolt for a stronger hold than nylon-insert locknuts. Also known as reversible locknuts, they can be threaded on from either end. The strength of the bolt should match the strength of the nut to prevent damaging threads. They're not reusable.
For technical drawings and 3-D models, click on a part number.
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.
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 |



























