Thread Size Thread Size |
---|
Material Material |
---|
|
Specifications Met Specifications Met |
---|
|
Height Height |
---|

Locking Type Locking Type |
---|
![]() | ![]() |
Cotter Pin | Nylon Insert |
Hex Nut Profile Hex Nut Profile |
---|
![]() | ![]() |
Standard | Extra Wide |
![]() | |
Thin |
Fastener Strength Grade/Class Fastener StrengthGrade/Class |
---|
Width Width |
---|

RoHS (Restriction of Hazardous Substances) RoHS (Restriction ofHazardous Substances) |
---|
|
DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense AcquisitionRegulations Supplement) |
---|
REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration,Evaluation, Authorization and Restriction of Chemicals) |
---|
|
About Nuts, Materials, and Finishes
More
Metric Medium-Strength Steel Locknuts for use with Cotter Pins—Class 8



Often referred to as castle nuts, secure these by inserting a cotter pin or safety wire through the slots and a drilled hole in your bolt for mild loosening resistance. They’re not recommended for use on parts exposed to high vibration because the pin is prone to shearing under prolonged stress. Height includes the slots. Cotter pins are not included.
Zinc-plated steel locknuts resist corrosion in wet environments.
Steel locknuts are best for dry environments, since moisture will cause them to rust. They are weldable and can be painted or finished.
For technical drawings and 3-D models, click on a part number.
Thread | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
Size | Pitch, mm | Wd., mm | Ht., mm | For Cotter Pin Dia., mm | Min. Slot Wd., mm | Min. Slot Dp., mm | Specifications Met | Pkg. Qty. | Pkg. | |
Zinc-Plated Steel—Class 8 | ||||||||||
M6 | 1 | 10 | 7.5 | 1.6 | 2 | 2.5 | DIN 935 | 5 | 000000000 | 00000 |
M8 | 1.25 | 13 | 9.5 | 2 | 2.5 | 3 | DIN 935 | 5 | 000000000 | 0000 |
M10 | 1.5 | 17 | 12 | 2.5 | 2.8 | 4 | DIN 935 | 5 | 000000000 | 0000 |
M12 | 1.5 | 19 | 15 | 3.2 | 3.5 | 5 | DIN 935 | 5 | 000000000 | 0000 |
M12 | 1.75 | 19 | 15 | 3.2 | 3.5 | 5 | DIN 935 | 5 | 000000000 | 0000 |
M14 | 1.5 | 22 | 16 | 3.2 | 3.5 | 5 | DIN 935 | 1 | 000000000 | 0000 |
M14 | 2 | 22 | 16 | 3.2 | 3.5 | 5 | DIN 935 | 1 | 000000000 | 0000 |
M16 | 1.5 | 24 | 19 | 4 | 4.5 | 6 | DIN 935 | 10 | 000000000 | 00000 |
M16 | 2 | 24 | 19 | 4 | 4.5 | 6 | DIN 935 | 5 | 000000000 | 0000 |
M18 | 2.5 | 27 | 21 | 4 | 4.5 | 6 | DIN 935 | 1 | 000000000 | 0000 |
M20 | 2.5 | 30 | 22 | 4 | 4.5 | 6 | DIN 935 | 5 | 000000000 | 00000 |
M24 | 2 | 36 | 27 | 5 | 5.5 | 8 | DIN 935 | 1 | 000000000 | 0000 |
M24 | 3 | 36 | 27 | 5 | 5.5 | 8 | DIN 935 | 1 | 000000000 | 0000 |
M27 | 3 | 41 | 30 | 5 | 5.5 | 8 | DIN 935 | 1 | 000000000 | 00000 |
M30 | 3.5 | 46 | 33 | 6.3 | 7 | 9 | DIN 935 | 1 | 000000000 | 00000 |
Steel—Class 8 | ||||||||||
M12 | 1.5 | 19 | 15 | 3.2 | 3.5 | 5 | DIN 935 | 10 | 000000000 | 0000 |
M14 | 1.5 | 22 | 16 | 3.2 | 3.5 | 5 | DIN 935 | 1 | 000000000 | 0000 |
M14 | 2 | 22 | 16 | 3.2 | 3.5 | 5 | DIN 935 | 1 | 000000000 | 0000 |
M16 | 1.5 | 24 | 19 | 4 | 4.5 | 6 | DIN 935 | 1 | 000000000 | 0000 |
M16 | 2 | 24 | 19 | 4 | 4.5 | 6 | DIN 935 | 1 | 000000000 | 0000 |
M18 | 2.5 | 27 | 21 | 4 | 4.5 | 6 | DIN 935 | 1 | 000000000 | 0000 |
M20 | 2.5 | 30 | 22 | 4 | 4.5 | 6 | DIN 935 | 1 | 000000000 | 0000 |
M24 | 3 | 36 | 27 | 5 | 5.5 | 8 | DIN 935 | 1 | 000000000 | 0000 |
M30 | 3.5 | 46 | 33 | 6.3 | 7 | 9 | DIN 935 | 1 | 000000000 | 00000 |
M36 | 3 | 55 | 38 | 6.3 | 7 | 9 | DIN 935 | 1 | 000000000 | 00000 |
M36 | 4 | 55 | 38 | 6.3 | 7 | 9 | DIN 935 | 1 | 000000000 | 00000 |
M42 | 4.5 | 65 | 46 | 8 | 9 | 12 | DIN 935 | 1 | 000000000 | 00000 |
M48 | 5 | 75 | 50 | 8 | 9 | 12 | DIN 935 | 1 | 000000000 | 00000 |
M56 | 5.5 | 85 | 57 | 8 | 9 | 12 | DIN 935 | 1 | 000000000 | 00000 |
Mil. Spec. Low-Strength Steel Thin Nylon-Insert Locknuts

Choose these locknuts for their adherence to strict military standards for material and construction. About half the height of standard nylon-insert locknuts, use them in light duty low-clearance applications or jam one against a hex nut to hold it in place. The nylon insert grips the bolt to resist loosening without damaging threads. They're reusable, but their holding power lessens with each use. A cadmium yellow-chromate plating provides corrosion resistance in wet environments and adds lubricity so they thread on smoothly.
For technical drawings and 3-D models, click on a part number.
Thread Size | Wd. | Ht. | Insert Max. Temp., °F | Specifications Met | Pkg. Qty. | Pkg. | |
Cadmium Yellow-Chromate Plated Steel | |||||||
---|---|---|---|---|---|---|---|
4-40 | 1/4" | 1/8" | 250° | MS21083N04, NASM21083 | 10 | 000000000 | 000000 |
6-32 | 5/16" | 9/64" | 250° | MS21083N06, NASM21083 | 10 | 000000000 | 00000 |
8-32 | 11/32" | 3/16" | 250° | MS21083N08, NASM21083 | 10 | 000000000 | 0000 |
10-32 | 3/8" | 3/16" | 250° | MS21083N3, NASM21083 | 10 | 000000000 | 0000 |
1/4"-28 | 7/16" | 7/32" | 250° | MS21083N4, NASM21083 | 10 | 000000000 | 0000 |
1/2"-20 | 3/4" | 5/16" | 250° | MS21083N8, NASM21083 | 1 | 000000000 | 0000 |
High-Strength Steel Extra-Wide Hex Nuts for Structural Applications—Grade C




These nuts are designed to secure ASTM A325 bolts in structural joints. Also known as heavy hex nuts, they are about 10% wider and taller than standard hex nuts and distribute the load over a large area.
Steel nuts without a finish are weldable and ready to be painted or finished.
Black-oxide steel nuts have a dark surface color and are mildly corrosion resistant in dry environments.
Hot-dipped galvanized steel nuts have a thick coating for good corrosion resistance. They must be used with other hot-dipped galvanized fasteners.
For technical drawings and 3-D models, click on a part number.
Thread Size | Wd. | Ht. | Specifications Met | Pkg. Qty. | Pkg. | |
Steel—ASTM Grade C | ||||||
---|---|---|---|---|---|---|
1/2"-13 | 7/8" | 31/64" | ASTM A563 | 25 | 000000000 | 000000 |
5/8"-11 | 1 1/16" | 39/64" | ASTM A563 | 10 | 000000000 | 0000 |
3/4"-10 | 1 1/4" | 47/64" | ASTM A563 | 10 | 000000000 | 00000 |
7/8"-9 | 1 7/16" | 55/64" | ASTM A563 | 10 | 000000000 | 00000 |
1"-8 | 1 5/8" | 63/64" | ASTM A563 | 5 | 000000000 | 00000 |
1 1/8"-7 | 1 3/4" | 1 7/64" | ASTM A563 | 1 | 000000000 | 0000 |
1 1/4"-7 | 2" | 1 7/32" | ASTM A563 | 1 | 000000000 | 0000 |
1 1/2"-6 | 2 3/8" | 1 15/32" | ASTM A563 | 1 | 000000000 | 00000 |
Black-Oxide Steel—ASTM Grade C | ||||||
1/2"-13 | 7/8" | 31/64" | ASTM A563 | 10 | 000000000 | 0000 |
5/8"-11 | 1 1/16" | 39/64" | ASTM A563 | 10 | 000000000 | 00000 |
3/4"-10 | 1 1/4" | 47/64" | ASTM A563 | 5 | 000000000 | 0000 |
7/8"-9 | 1 7/16" | 55/64" | ASTM A563 | 1 | 000000000 | 0000 |
1"-8 | 1 5/8" | 63/64" | ASTM A563 | 1 | 000000000 | 0000 |
1 1/8"-7 | 1 3/4" | 1 7/64" | ASTM A563 | 1 | 000000000 | 0000 |
1 1/4"-7 | 2" | 1 7/32" | ASTM A563 | 1 | 000000000 | 00000 |
1 1/2"-6 | 2 3/8" | 1 15/32" | ASTM A563 | 1 | 000000000 | 00000 |
Hot-Dipped Galvanized Steel—ASTM Grade C | ||||||
1/2"-13 | 7/8" | 31/64" | ASTM A563 | 5 | 000000000 | 0000 |
5/8"-11 | 1 1/16" | 39/64" | ASTM A563 | 1 | 000000000 | 0000 |
3/4"-10 | 1 1/4" | 47/64" | ASTM A563 | 1 | 000000000 | 0000 |
7/8"-9 | 1 7/16" | 55/64" | ASTM A563 | 1 | 000000000 | 00000 |
1"-8 | 1 5/8" | 63/64" | ASTM A563 | 1 | 000000000 | 00000 |
1 1/8"-7 | 1 3/4" | 1 7/64" | ASTM A563 | 1 | 000000000 | 00000 |
1 1/4"-7 | 2" | 1 7/32" | ASTM A563 | 1 | 000000000 | 00000 |
Extreme-Strength Steel Extra-Wide Hex Nuts for Structural Applications—Grade DH


These nuts are designed to secure ASTM A325 bolts in structural joints. Also known as heavy hex nuts, they are about 10% wider and taller than standard hex nuts.
Hot-dipped galvanized steel nuts have a thick coating for good corrosion resistance. They must be used with other hot-dipped galvanized fasteners.
For technical drawings and 3-D models, click on a part number.
Thread Size | Wd. | Ht. | Specifications Met | Pkg. Qty. | Pkg. | |
Hot-Dipped Galvanized Steel—ASTM Grade DH | ||||||
---|---|---|---|---|---|---|
1/2"-13 | 7/8" | 31/64" | ASTM A563 | 25 | 000000000 | 000000 |
5/8"-11 | 1 1/16" | 39/64" | ASTM A563 | 10 | 000000000 | 00000 |
3/4"-10 | 1 1/4" | 47/64" | ASTM A563 | 10 | 000000000 | 00000 |
7/8"-9 | 1 7/16" | 55/64" | ASTM A563 | 10 | 000000000 | 00000 |
1"-8 | 1 5/8" | 63/64" | ASTM A563 | 5 | 000000000 | 00000 |
1 1/4"-7 | 2" | 1 7/32" | ASTM A563 | 1 | 000000000 | 0000 |
1 1/2"-6 | 2 3/8" | 1 15/32" | ASTM A563 | 1 | 000000000 | 00000 |
Mil. Spec. 18-8 Stainless Steel Thin Hex Nuts

Choose these nuts for their adherence to strict military standards for material and construction. Made of 18-8 stainless steel, they have good chemical resistance and may be mildly magnetic. Also known as jam nuts, they are about half the height of standard hex nuts. Use them in low-clearance applications or jam one against another nut to hold it in place.
For technical drawings and 3-D models, click on a part number.
Thread Size | Wd. | Ht. | Specifications Met | Pkg. Qty. | Pkg. | |
18-8 Stainless Steel | ||||||
---|---|---|---|---|---|---|
1/4"-20 | 7/16" | 5/32" | Fed. Spec. FF-N-836, MS35691-3 | 5 | 000000000 | 000000 |
1/4"-28 | 7/16" | 5/32" | Fed. Spec. FF-N-836, MS35691-7 | 1 | 000000000 | 0000 |
5/16"-18 | 1/2" | 3/16" | Fed. Spec. FF-N-836, MS35691-11 | 5 | 000000000 | 00000 |
5/16"-24 | 1/2" | 3/16" | Fed. Spec. FF-N-836, MS35691-15 | 5 | 000000000 | 00000 |
3/8"-16 | 9/16" | 7/32" | Fed. Spec. FF-N-836, MS35691-19 | 1 | 000000000 | 0000 |
3/8"-24 | 9/16" | 7/32" | Fed. Spec. FF-N-836, MS35691-23 | 1 | 000000000 | 0000 |
7/16"-14 | 11/16" | 1/4" | Fed. Spec. FF-N-836, MS35691-27 | 1 | 000000000 | 0000 |
7/16"-20 | 11/16" | 1/4" | Fed. Spec. FF-N-836, MS35691-31 | 1 | 000000000 | 0000 |
1/2"-13 | 3/4" | 5/16" | Fed. Spec. FF-N-836, MS35691-35 | 1 | 000000000 | 0000 |
1/2"-20 | 3/4" | 5/16" | Fed. Spec. FF-N-836, MS35691-39 | 1 | 000000000 | 0000 |
5/8"-11 | 15/16" | 3/8" | Fed. Spec. FF-N-836, MS35691-51 | 1 | 000000000 | 00000 |
5/8"-18 | 15/16" | 3/8" | Fed. Spec. FF-N-836, MS35691-55 | 1 | 000000000 | 00000 |