Spinning Washer Nuts | McMaster-Carr

Filter by

System of Measurement

Thread Size

Nut Type

Width

Finish

Flange Diameter

Material

Flange Thickness

Thread Pitch

Hex Nut Profile

Thread Type

Washer Material

Thread Spacing

Performance

Thread Fit

Unified Standard Class 2B

Export Control Classification Number (ECCN)

EAR99

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

RoHS

REACH

DFARS Specialty Metals

Exempt

Not Compliant

Fastener Strength Rating

Washer OD

82 Products

Rotating Flange Nuts

The head of these nuts rotates while the flange remains stationary, so you won't scratch the surface of finished parts as you tighten. They distribute pressure evenly across the mounting surface without the need for a separate washer. Also known as collar nuts.

Steel

Black-Oxide Steel—Typically chosen for their appearance, these nuts have a dark, matte coating that creates a finished look. They offer minimal corrosion resistance, so they're best for dry environments.

				Flange
	Thread Size	Wd.	Ht.	Dia.	Thk.	Material		Each
Black-Oxide Steel



		1/4"-20	1/2"	3/8"	5/8"	0.13"	Steel	90477A029	00000


		1/4"-28	1/2"	3/8"	5/8"	0.13"	Steel	90477A111	0000
		5/16"-18	9/16"	7/16"	3/4"	0.14"	Steel	90477A030	0000
		5/16"-24	9/16"	7/16"	3/4"	0.14"	Steel	90477A112	0000
		3/8"-16	11/16"	17/32"	7/8"	0.16"	Steel	90477A031	0000
		3/8"-24	11/16"	17/32"	7/8"	0.16"	Steel	90477A113	0000
		1/2"-13	7/8"	23/32"	1 1/8"	0.22"	Steel	90477A033	0000
		1/2"-20	7/8"	23/32"	1 1/8"	0.22"	Steel	90477A114	0000
		5/8"-11	1 1/16"	29/32"	1 3/8"	0.25"	Steel	90477A035	0000
		5/8"-18	1 1/16"	29/32"	1 3/8"	0.25"	Steel	90477A115	0000
		3/4"-10	1 1/4"	1 1/64"	1 5/8"	0.28"	Steel	90477A036	00000


		3/4"-16	1 1/4"	1 1/64"	1 5/8"	0.28"	Steel	90477A116	00000
		7/8"-9	1 7/16"	1 1/8"	1 3/4"	0.44"	Steel	90477A037	00000
		7/8"-14	1 7/16"	1 1/8"	1 3/4"	0.44"	Steel	90477A117	00000
		1"-8	1 5/8"	1 15/64"	2"	0.47"	Steel	90477A038	00000
		1"-12	1 5/8"	1 15/64"	2"	0.47"	Steel	90477A118	00000
		M6 × 1 mm	13 mm	9.5 mm	15.9 mm	3.2 mm	Steel	90477A119	0000
		M8 × 1.25 mm	14 mm	11.1 mm	19 mm	3.6 mm	Steel	90477A121	0000
		M10 × 1.5 mm	17 mm	13.5 mm	22.2 mm	5.6 mm	Steel	90477A122	0000
		M12 × 1.75 mm	22 mm	18.3 mm	28.6 mm	5.6 mm	Steel	90477A123	0000
		M16 × 2 mm	27 mm	23 mm	34.9 mm	6.4 mm	Steel	90477A124	0000


		M20 × 2.5 mm	37 mm	28.6 mm	44.5 mm	11.1 mm	Steel	90477A125	00000
		M24 × 3 mm	41 mm	31.3 mm	50.8 mm	11.9 mm	Steel	90477A126	00000

Locknuts with External-Tooth Lock Washer

To save on assembly time, these locknuts combine a hex nut with a free-spinning lock washer, so you can twist them into place by hand. Once the nut is against your material surface, tighten it down with a wrench or socket to get the teeth to bite. Although these nuts install more quickly than nylon-insert locknuts, they don't hold up as well against vibration and can mar your material. As long as the washer stays intact, you can reuse them. Also known as Keps and K-lock nuts.

Medium-Strength Steel

These Grade 5 or Class 8 nuts are your go-to for fastening most machinery and equipment. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

Black-Zinc-Plated Steel—The dark zinc plating withstands occasional exposure to moisture while creating a finished look.

	Wd., mm	Ht., mm	Fastener Strength Grade/Class	Washer OD, mm	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M3 × 0.5 mm	5.5	3.3	Class 8	7.1	100	93825A110	000000


	M4 × 0.7 mm	7	4.1	Class 8	8.5	100	93825A120	00000
	M5 × 0.8 mm	8	5.2	Class 8	9.5	100	93825A130	00000
	M6 × 1 mm	10	6.2	Class 8	12	100	93825A140	00000
	M8 × 1.25 mm	13	8.5	Class 8	15.5	25	93825A160	0000
	M10 × 1.5 mm	17	9.7	Class 8	20.1	10	93825A170	00000


	Black-Zinc-Plated Steel



			M3 × 0.5 mm	5.5	3	Class 8	7.1	100	93825A210	00000


			M4 × 0.7 mm	7	4.1	Class 8	8.5	100	93825A220	00000
			M5 × 0.8 mm	8	5.2	Class 8	9.5	100	93825A230	00000
			M6 × 1 mm	10	6.2	Class 8	12	50	93825A240	00000
			M8 × 1.25 mm	13	8.5	Class 8	15.5	25	93825A250	00000
			M10 × 1.5 mm	17	9.7	Class 8	20.1	10	93825A260	00000

Low-Strength Steel

Rated Grade 2, Class 6, or lower, these locknuts are about half as strong as medium-strength steel nuts. Use them with screws that have a similar strength rating to avoid stripping threads during installation.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

Black-Zinc-Plated Steel—The dark zinc plating withstands occasional exposure to moisture while creating a finished look.

	Wd.	Ht.	Washer OD	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	4-40	1/4"	7/64"	0.281"	100	90675A005	00000


	5-40	5/16"	9/64"	0.344"	100	90675A245	0000
	6-32	5/16"	9/64"	0.344"	100	90675A007	0000
	8-32	11/32"	5/32"	0.375"	100	90675A009	0000
	10-24	3/8"	5/32"	0.406"	100	90675A011	0000
	10-32	3/8"	5/32"	0.406"	100	90675A195	0000
	12-24	7/16"	3/16"	0.5"	50	90675A255	0000
	1/4"-20	7/16"	15/64"	0.5"	100	90675A029	0000
	1/4"-28	7/16"	15/64"	0.5"	100	90675A215	0000
	5/16"-18	1/2"	21/64"	0.578"	100	90675A030	00000
	5/16"-24	1/2"	5/16"	0.592"	50	90675A225	00000


	3/8"-16	9/16"	25/64"	0.656"	100	90675A031	00000
	3/8"-24	9/16"	25/64"	0.656"	100	90675A235	00000
	1/2"-13	3/4"	31/64"	0.891"	10	90675A265	0000


	Black-Zinc-Plated Steel



			4-40	1/4"	1/8"	0.281"	100	90328A101	0000


			6-32	5/16"	9/64"	0.344"	100	90328A102	0000
			8-32	11/32"	5/32"	0.375"	100	90328A103	0000
			10-24	3/8"	5/32"	0.406"	100	90328A104	0000
			10-32	3/8"	5/32"	0.406"	100	90328A105	0000
			1/4"-20	7/16"	7/32"	0.5"	100	90328A106	00000

Corrosion-Resistant Stainless Steel

18-8 Stainless Steel—The choice for wet and outdoor environments, these locknuts resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.

Black-Oxide 18-8 Stainless Steel—Typically chosen for their appearance, these nuts have a dark, matte coating to create a finished look. They resist rust in wet and outdoor environments, but won't hold up to the harsh chemicals that 316 stainless steel can.

	Wd.	Ht.	Washer OD	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	4-40	1/4"	1/8"	0.281"	100	96278A005	000000


	4-48	1/4"	1/8"	0.281"	100	96278A101	00000
	6-32	5/16"	9/64"	0.344"	100	96278A007	00000
	8-32	11/32"	11/64"	0.375"	100	96278A009	00000
	10-24	3/8"	11/64"	0.406"	100	96278A011	00000
	10-32	3/8"	11/64"	0.406"	100	96278A411	00000
	12-24	7/16"	11/64"	0.506"	50	96278A111	00000
	1/4"-20	7/16"	15/64"	0.5"	50	96278A511	00000
	1/4"-28	7/16"	15/64"	0.5"	50	96278A515	00000
	5/16"-18	1/2"	21/64"	0.578"	25	96278A519	0000
	5/16"-24	1/2"	21/64"	0.578"	25	96278A523	00000


	3/8"-16	9/16"	25/64"	0.656"	25	96278A527	00000
	3/8"-24	9/16"	25/64"	0.656"	10	96278A531	0000
	1/2"-13	3/4"	7/16"	0.898"	10	96278A112	0000
	M3 × 0.5 mm	5.5 mm	3.3 mm	6.5 mm	50	90923A216	00000
	M4 × 0.7 mm	7 mm	4.1 mm	8.2 mm	50	90923A219	00000
	M5 × 0.8 mm	8 mm	5.2 mm	9.5 mm	25	90923A222	0000
	M6 × 1 mm	10 mm	6.2 mm	11.5 mm	25	90923A227	0000
	M8 × 1.25 mm	13 mm	8.5 mm	15.1 mm	5	90923A241	0000
	M10 × 1.5 mm	17 mm	9.7 mm	19.2 mm	5	90923A282	00000


	Black-Oxide 18-8 Stainless Steel



			M3 × 0.5 mm	5.5 mm	3.3 mm	6.5 mm	25	90923A231	0000


			M4 × 0.7 mm	7 mm	4.1 mm	8.2 mm	25	90923A232	00000
			M5 × 0.8 mm	8 mm	5.2 mm	9.5 mm	25	90923A233	00000
			M6 × 1 mm	10 mm	6.2 mm	11.5 mm	25	90923A234	00000

Narrow-Profile Locknuts with External-Tooth Lock Washer

Since they're about 20% narrower, these locknuts fit in tight spaces where standard-profile nuts won't fit. They combine a hex nut with a free-spinning lock washer, so you can twist them into place by hand and save on assembly time. Once the nut is against your material surface, tighten it down with a wrench or socket to get the teeth to bite. Although these nuts install more quickly than nylon-insert locknuts, they don't hold up as well against vibration and can mar your material. As long as the washer stays intact, you can reuse them. Also known as Keps and K-lock nuts.

Low-Strength Steel

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

	Wd.	Ht.	Washer OD	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	6-32	1/4"	1/8"	0.281"	100	90413A101	000000


	8-32	5/16"	9/64"	0.344"	100	90413A102	00000

Corrosion-Resistant Stainless Steel

18-8 Stainless Steel—The choice for wet and outdoor environments, these locknuts resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.

	Wd.	Ht.	Washer OD	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	6-32	1/4"	1/8"	0.287"	100	96278A113	000000