Jam Locknuts | McMaster-Carr

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Material

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Finish

Cadmium Yellow-Chromate Plated

Corrosion-Resistant Coated

Phosphate Coated

Zinc Plated

Zinc Yellow-Chromate Plated

Width

Thread Type

Thread Direction

Thread Pitch

Performance

Specifications Met

Thread Fit

Unified Standard Class 2B

Unified Standard Class 3B

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Coarse

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Fastener Strength Grade/Class

ASTM Grade C

SAE Grade 5

SAE Grade 8

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DFARS Specialty Metals

Compliant

Exempt

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

Yes

Export Control Classification Number (ECCN)

EAR99

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290 Products

Locking Type

Nylon Insert

Versatile and economical—the most commonly used locknuts

214 products

Flex-Top

Stronger hold than nylon-insert and distorted-thread locknuts

67 products

Locking Type

Steel Insert

The most vibration-resistant hold we offer

9 products

Performance

Heavy Vibration Resistant

Use in equipment with constant vibration, such as engines

67 products

Thin-Profile Nylon-Insert Locknuts

About half the height of standard-profile locknuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

High-Strength Steel

Rated Grade 8, Grade C, or Class 10, these locknuts are about 25% stronger than medium-strength steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Zinc-Yellow-Chromate-Plated Steel—With a more durable finish than clear zinc plating, these nuts are suitable for most wet and outdoor environments. However, they won't hold up to the harsh chemicals that stainless steel can.

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

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

	Wd.	Ht.	Fastener Strength Grade/Class	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Yellow-Chromate-Plated Steel



	1/4"-20	7/16"	13/64"	SAE Grade 8	Not Rated	100	94945A205	000000


	1/4"-28	7/16"	13/64"	SAE Grade 8	250	10	94945A139	0000
	5/16"-18	1/2"	1/4"	SAE Grade 8	Not Rated	100	94945A213	00000
	5/16"-24	1/2"	1/4"	SAE Grade 8	250	10	94945A119	00000
	3/8"-16	9/16"	17/64"	SAE Grade 8	Not Rated	100	94945A217	00000
	3/8"-24	9/16"	17/64"	SAE Grade 8	Not Rated	50	94945A218	00000
	7/16"-14	5/8"	5/16"	SAE Grade 8	Not Rated	25	94945A260	00000
	7/16"-20	5/8"	5/16"	SAE Grade 8	Not Rated	25	94945A270	00000
	1/2"-13	3/4"	5/16"	SAE Grade 8	Not Rated	25	94945A224	00000
	1/2"-20	3/4"	5/16"	SAE Grade 8	250	5	94945A121	0000
	5/8"-11	15/16"	25/64"	SAE Grade 8	Not Rated	10	94945A227	0000


	5/8"-18	15/16"	25/64"	SAE Grade 8	250	5	94945A122	0000
	3/4"-16	1 1/16"	13/32"	SAE Grade 8	250	1	94945A123	0000
	7/8"-14	1 1/4"	15/32"	SAE Grade 8	250	1	94945A124	0000
	1"-14	1 7/16"	35/64"	SAE Grade 8	250	1	94945A125	0000
	1 1/4"-12	1 13/16"	3/4"	SAE Grade 8	Not Rated	1	94945A280	00000
	1 1/2"-12	2 3/16"	51/64"	SAE Grade 8	Not Rated	1	94945A290	00000


	Zinc-Plated Steel



			5/16"-24	1/2"	1/4"	SAE Grade 8	220	10	94945A215	0000


			1/2"-20	3/4"	5/16"	SAE Grade 8	220	5	94945A225	0000
			5/8"-18	15/16"	25/64"	SAE Grade 8	220	5	94945A230	0000
			3/4"-16	1 1/16"	13/32"	SAE Grade 8	220	1	94945A235	0000
			7/8"-14	1 1/4"	15/32"	SAE Grade 8	220	1	94945A240	0000
			1"-14	1 7/16"	35/64"	SAE Grade 8	220	1	94945A250	0000
			1 1/8"-12	1 53/64"	41/64"	SAE Grade 8	220	1	94945A251	00000


			Black-Oxide Steel



					1/4"-20	7/16"	13/64"	SAE Grade 8	250	25	94945A131	00000


					1/4"-28	7/16"	13/64"	SAE Grade 8	250	10	94945A132	00000
					5/16"-18	1/2"	1/4"	SAE Grade 8	250	25	94945A133	00000
					5/16"-24	1/2"	1/4"	SAE Grade 8	250	10	94945A111	00000
					3/8"-16	9/16"	17/64"	SAE Grade 8	250	10	94945A134	0000
					3/8"-24	9/16"	17/64"	SAE Grade 8	250	10	94945A135	0000
					7/16"-20	5/8"	5/16"	SAE Grade 8	250	10	94945A136	00000
					1/2"-13	3/4"	5/16"	SAE Grade 8	250	10	94945A137	00000
					1/2"-20	3/4"	5/16"	SAE Grade 8	250	5	94945A112	0000
					5/8"-11	15/16"	25/64"	SAE Grade 8	250	5	94945A138	00000
					5/8"-18	15/16"	25/64"	SAE Grade 8	250	5	94945A113	00000


					3/4"-16	1 1/16"	13/32"	SAE Grade 8	250	1	94945A114	0000
					7/8"-14	1 1/4"	15/32"	SAE Grade 8	250	1	94945A115	0000
					1"-14	1 7/16"	35/64"	SAE Grade 8	250	1	94945A116	0000
					1 1/4"-12	1 13/16"	47/64"	SAE Grade 8	250	1	94945A118	00000
1 1/2"-12					2 11/64"	51/64"	SAE Grade 8	250	1	94945A117	00000

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.

	Wd.	Ht.	Fastener Strength Grade/Class	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	5/8"-11	15/16"	25/64"	SAE Grade 5	220	5	91342A210	000000


	5/8"-18	15/16"	25/64"	SAE Grade 5	220	5	91342A220	00000
	3/4"-10	1 1/16"	13/32"	SAE Grade 5	220	5	91342A230	00000
	3/4"-16	1 1/16"	13/32"	SAE Grade 5	220	10	91342A240	00000
	7/8"-14	1 1/4"	15/32"	SAE Grade 5	220	1	91342A250	0000
	1"-8	1 7/16"	35/64"	SAE Grade 5	220	1	91342A260	0000
	1"-14	1 7/16"	35/64"	SAE Grade 5	220	1	91342A270	0000
	1 1/8"-7	1 5/8"	41/64"	SAE Grade 5	220	1	91342A280	00000
	1 1/4"-7	1 13/16"	3/4"	SAE Grade 5	220	1	91342A290	00000
	1 1/4"-12	1 13/16"	3/4"	SAE Grade 5	220	1	91342A320	00000
	1 1/2"-6	2 3/16"	51/64"	SAE Grade 5	220	1	91342A310	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.

Black-Corrosion-Resistant-Coated Steel—These nuts combine a finished appearance with the rust resistance of stainless steel. The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.

	Thread Size	Wd.	Ht.	Insert Max. Temp., ° F	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		2-56	1/4"	7/64"	220	—	100	90633A004	000000


		4-40	1/4"	7/64"	220	—	100	90633A005	0000
		5-40	1/4"	7/64"	220	—	100	90633A006	0000
		6-32	5/16"	1/8"	220	—	100	90633A007	00000
		8-32	11/32"	11/64"	220	—	100	90633A009	0000
		10-24	3/8"	11/64"	220	—	100	90633A011	0000
		10-32	3/8"	11/64"	220	—	100	90633A411	0000
		12-24	7/16"	13/64"	220	—	100	90633A412	0000
		1/4"-20	7/16"	13/64"	220	—	100	90566A029	0000
		1/4"-28	7/16"	13/64"	220	—	100	90566A210	0000
		5/16"-18	1/2"	1/4"	220	—	100	90566A030	0000


		5/16"-24	1/2"	1/4"	220	—	100	90566A215	0000
		3/8"-16	9/16"	17/64"	220	—	100	90566A031	0000
		3/8"-24	9/16"	17/64"	220	—	100	90566A220	0000
		7/16"-14	5/8"	5/16"	220	—	100	90566A032	00000
		7/16"-20	5/8"	5/16"	220	—	100	90566A225	00000
		1/2"-13	3/4"	5/16"	220	—	100	90566A033	00000
		1/2"-20	3/4"	5/16"	220	—	100	90566A230	00000
		9/16"-12	7/8"	23/64"	220	—	100	90566A231	00000
		9/16"-18	7/8"	23/64"	220	—	100	90566A232	00000
		5/8"-11	15/16"	25/64"	220	—	50	90566A035	00000


		5/8"-18	15/16"	25/64"	220	—	50	90566A235	00000
		3/4"-10	1 1/16"	13/32"	220	—	10	90566A240	0000
		3/4"-16	1 1/16"	13/32"	220	—	10	90566A243	0000
		7/8"-9	1 1/4"	15/32"	220	—	5	90566A246	0000
		7/8"-14	1 1/4"	15/32"	220	—	5	90566A249	0000
		1"-8	1 7/16"	35/64"	220	—	1	90566A253	0000
		1"-14	1 7/16"	35/64"	220	—	1	90566A256	0000
		1 1/8"-7	1 5/8"	41/64"	220	—	1	90566A259	0000
		1 1/4"-7	1 13/16"	3/4"	220	—	1	90566A262	0000
		1 1/4"-12	1 13/16"	3/4"	220	—	1	90566A265	0000


		1 3/8"-6	2"	51/64"	220	—	1	90566A268	0000
		1 1/2"-6	2 3/16"	51/64"	220	—	1	90566A271	0000
		M3 × 0.5 mm	5.5 mm	3.9 mm	245	ISO 10511	25	90453A111	00000
		M4 × 0.7 mm	7 mm	5 mm	245	ISO 10511	25	90453A112	0000
		M5 × 0.8 mm	8 mm	5 mm	245	ISO 10511	25	90453A113	0000
		M6 × 1 mm	10 mm	6 mm	245	ISO 10511	10	90453A114	0000
		M8 × 1.25 mm	13 mm	6.8 mm	245	ISO 10511	5	90453A115	0000
		M10 × 1.5 mm	16 mm	8.6 mm	245	ISO 10511	5	90453A116	0000
		M12 × 1.75 mm	18 mm	10.3 mm	245	ISO 10511	5	90453A117	0000
		M14 × 2 mm	21 mm	11.4 mm	245	ISO 10511	5	90453A118	0000


		M16 × 2 mm	24 mm	12.5 mm	245	ISO 10511	1	90453A119	0000
		M18 × 2.5 mm	26 mm	13 mm	245	ISO 10511	1	90453A121	0000
		M20 × 2.5 mm	30 mm	14.9 mm	245	ISO 10511	1	90453A122	0000
		M24 × 3 mm	36 mm	17.8 mm	245	ISO 10511	1	90453A123	00000


		Black-Zinc-Plated Steel



6-32				5/16"	1/8"	220	—	25	94627A110	0000


8-32	11/32"			11/64"	220	—	25	94627A120	0000
10-24	3/8"			11/64"	220	—	25	94627A130	0000
10-32	3/8"			11/64"	220	—	25	94627A140	0000
12-24	7/16"			13/64"	220	—	25	94627A150	0000
1/4"-20	7/16"			13/64"	220	—	25	94627A160	0000
5/16"-18	1/2"			1/4"	220	—	10	94627A170	0000
3/8"-16	9/16"			17/64"	220	—	10	94627A180	0000


Black-Corrosion-Resistant-Coated Steel



				6-32	5/16"	1/8"	220	—	5	91581A315	0000


				8-32	11/32"	11/64"	220	—	5	91581A325	0000
				10-24	3/8"	11/64"	220	—	5	91581A335	0000
				10-32	3/8"	11/64"	220	—	5	91581A345	0000
				1/4"-20	7/16"	13/64"	220	—	5	91581A355	0000
				5/16"-18	1/2"	1/4"	220	—	5	91581A365	0000
				3/8"-16	9/16"	17/64"	220	—	5	91581A375	0000
				1/2"-13	3/4"	5/16"	220	—	5	91581A385	0000

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.

316 Stainless Steel—Our most corrosion-resistant nuts, these hold up in just about any environment. They won't degrade from exposure to weather, salt water, and most chemicals.

	Thread Size	Wd.	Ht.	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
18-8 Stainless Steel



		4-40	1/4"	7/64"	220	50	90101A004	00000


		6-32	5/16"	1/8"	220	100	90101A007	00000
		8-32	11/32"	11/64"	220	100	90101A009	0000
		10-24	3/8"	11/64"	220	100	90101A011	00000
		10-32	3/8"	11/64"	220	50	90101A225	0000
		1/4"-20	7/16"	13/64"	220	50	90101A230	0000
		1/4"-28	7/16"	13/64"	220	50	90101A235	0000
		5/16"-18	1/2"	1/4"	220	50	90101A237	0000
		5/16"-24	1/2"	1/4"	220	50	90101A240	0000
		3/8"-16	9/16"	17/64"	220	25	90101A243	0000
		3/8"-24	9/16"	17/64"	220	25	90101A245	0000


		7/16"-14	5/8"	5/16"	220	10	90101A247	0000
		7/16"-20	5/8"	5/16"	220	5	90101A250	0000
		1/2"-13	3/4"	5/16"	220	10	90101A252	0000
		1/2"-20	3/4"	5/16"	220	5	90101A255	0000
		9/16"-18	7/8"	23/64"	220	1	90101A251	00000
		5/8"-11	15/16"	25/64"	220	1	90101A038	0000
		5/8"-18	15/16"	25/64"	220	1	90101A260	0000
		3/4"-10	1 1/16"	13/32"	220	1	90101A050	0000
		3/4"-16	1 1/16"	13/32"	220	1	90101A055	00000
		7/8"-9	1 1/4"	15/32"	220	1	90101A060	0000


		7/8"-14	1 1/4"	15/32"	220	1	90101A065	00000
		1"-8	1 7/16"	35/64"	220	1	90101A070	00000
		1"-14	1 7/16"	35/64"	220	1	90101A075	00000
		1 1/8"-7	1 5/8"	41/64"	220	1	90101A080	00000
		1 1/4"-7	1 13/16"	3/4"	220	1	90101A090	00000
		1 1/4"-12	1 13/16"	3/4"	220	1	90101A095	00000
		1 1/2"-6	2 3/16"	51/64"	220	1	90101A150	00000


		Black-Oxide 18-8 Stainless Steel



				4-40	1/4"	1/8"	220	100	90101A115	00000


				6-32	5/16"	9/64"	220	100	90101A116	00000
				8-32	11/32"	3/16"	220	100	90101A117	00000
				10-24	3/8"	3/16"	220	100	90101A118	00000
				10-32	3/8"	3/16"	220	100	90101A119	00000
				1/4"-20	7/16"	13/64"	220	50	90101A121	00000
				5/16"-18	1/2"	1/4"	220	50	90101A122	00000
				3/8"-16	9/16"	17/64"	220	50	90101A123	00000
				3/8"-24	9/16"	17/64"	220	50	90101A124	00000
				1/2"-13	3/4"	5/16"	220	5	90101A125	0000
				1/2"-20	3/4"	5/16"	220	5	90101A126	0000


				316 Stainless Steel



						10-24	3/8"	11/64"	220	50	97367A111	00000


10-32	3/8"					11/64"	220	50	97367A112	00000
1/4"-20	7/16"					13/64"	220	25	97367A113	0000
1/4"-28	7/16"					13/64"	220	50	97367A132	00000
5/16"-18	1/2"					1/4"	220	25	97367A114	00000
5/16"-24	1/2"					1/4"	220	50	97367A133	00000
3/8"-16	9/16"					17/64"	220	25	97367A115	00000
3/8"-24	9/16"					17/64"	220	25	97367A134	00000
7/16"-14	5/8"					5/16"	220	25	97367A135	00000
7/16"-20	5/8"					5/16"	220	25	97367A136	00000
1/2"-13	3/4"					5/16"	220	10	97367A116	00000


1/2"-20	3/4"					5/16"	220	10	97367A137	00000
3/4"-10	1 1/16"					25/64"	220	1	97367A131	00000

Mil. Spec. Thin-Profile Nylon-Insert Locknuts

These locknuts are manufactured and tested to strict U.S. military standards for material and construction. They are about half the height of standard-profile locknuts to fit in spaces with low clearance. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

Low-Strength Steel

Cadmium Yellow-Chromate-Plated Steel—These locknuts have good lubricity to thread on smoothly and ease installation. The plating also creates a barrier against rust that's comparable to zinc-yellow-chromate plating.

	Wd.	Ht.	Mil. Spec.	Insert Max. Temp., ° F	Specs. Met	Pkg. Qty.		Pkg.
Cadmium Yellow-Chromate-Plated Steel



	4-40	1/4"	1/8"	MS21083N04	250	NASM21083	10	95496A310	000000


	6-32	5/16"	9/64"	MS21083N06	250	NASM21083	10	95496A320	00000
	8-32	11/32"	3/16"	MS21083N08	250	NASM21083	10	95496A330	0000
	10-32	3/8"	3/16"	MS21083N3	250	NASM21083	10	95496A340	0000
	1/4"-28	7/16"	7/32"	MS21083N4	250	NASM21083	10	95496A350	0000
	1/2"-20	3/4"	5/16"	MS21083N8	250	NASM21083	1	95496A380	0000

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.	Mil. Spec.	Insert Max. Temp., ° F	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	2-56	1/4"	7/64"	MS21083C02	250	NASM21083	5	97231A480	000000


	4-40	1/4"	1/8"	MS21083C04	250	NASM21083	10	97231A410	00000
	6-32	5/16"	9/64"	MS21083C06	250	NASM21083	10	97231A420	00000
	8-32	11/32"	3/16"	MS21083C08	250	NASM21083	5	97231A430	0000
	10-32	3/8"	3/16"	MS21083C3	250	NASM21083	5	97231A440	00000
	1/4"-28	7/16"	7/32"	MS21083C4	250	NASM21083	5	97231A450	00000
	5/16"-24	1/2"	17/64"	MS21083C5	250	NASM21083	1	97231A460	0000
	3/8"-24	9/16"	9/32"	MS21083C6	250	NASM21083	1	97231A470	0000
	7/16"-20	11/16"	21/64"	MS21083C7	250	NASM21083	1	97231A510	00000
	1/2"-20	3/4"	5/16"	MS21083C8	250	NASM21083	1	97231A490	00000
	5/8"-18	15/16"	13/32"	MS21083C10	250	NASM21083	1	97231A520	00000

Thin-Heavy-Profile Nylon-Insert Locknuts

About half the height of standard-profile locknuts and 10% wider, these fit in spaces with low clearance and handle heavier loads by distributing them over a larger area. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

High-Strength Steel

Black-Phosphate-Coated Steel—The dark coating creates both a finished appearance and a barrier against rust that withstands occasional exposure to moisture.

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Fastener Strength Grade/Class	Insert Max. Temp., ° F		Each
Black-Phosphate-Coated Steel



	1 1/4"-12	2"	1 7/64"	ASTM Grade C	250	93126A110	00000


	1 1/2"-12	2 3/8"	1 5/16"	ASTM Grade C	250	93126A120	00000
	1 3/4"-12	2 3/4"	1 15/32"	ASTM Grade C	250	93126A130	00000
	2"-12	3 1/8"	1 43/64"	ASTM Grade C	250	93126A140	00000
	2 1/4"-12	3 1/2"	1 15/16"	ASTM Grade C	250	93126A150	00000
	2 1/2"-12	4"	2 3/16"	ASTM Grade C	250	93126A160	00000
	2 3/4"-12	4"	2 3/16"	ASTM Grade C	250	93126A170	00000
	3"-12	4 1/2"	2 41/64"	ASTM Grade C	250	93126A210	000000


	Steel



			1 1/8"-12	1 7/8"	1"	ASTM Grade C	250	93126A180	00000


			1 3/8"-12	2 13/64"	1 3/16"	ASTM Grade C	250	93126A190	00000

Low-Strength Steel

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

	Wd.	Ht.	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	1/4"-20	1/2"	9/32"	250	100	90652A029	000000


	5/16"-18	9/16"	5/16"	250	100	90652A030	00000
	3/8"-16	11/16"	13/32"	250	50	90652A040	00000
	1/2"-13	7/8"	17/32"	250	25	90652A050	00000
	5/8"-11	1 1/16"	39/64"	250	10	90652A055	00000
	3/4"-10	1 1/4"	45/64"	250	10	90652A060	00000
	1"-8	1 5/8"	57/64"	250	1	90652A065	0000
	1 1/4"-7	2"	1 7/64"	250	1	90652A070	00000


	Black-Corrosion-Resistant-Coated Steel



			1/4"-20	1/2"	9/32"	250	5	90652A810	0000


			5/16"-18	9/16"	5/16"	250	5	90652A820	0000
			3/8"-16	11/16"	13/32"	250	1	90652A830	0000
			1/2"-13	7/8"	17/32"	250	1	90652A840	0000

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.

316 Stainless Steel—Our most corrosion-resistant nuts, these hold up in just about any environment. They won't degrade from exposure to weather, salt water, and most chemicals.

	Wd.	Ht.	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	1/4"-20	1/2"	9/32"	250	25	90098A110	000000


	5/16"-18	9/16"	5/16"	250	20	90098A115	00000
	3/8"-16	11/16"	13/32"	250	10	90098A120	00000
	1/2"-13	7/8"	17/32"	250	1	90098A130	0000
	5/8"-11	1 1/16"	5/8"	250	1	90098A035	0000
	3/4"-10	1 1/4"	45/64"	250	1	90098A036	00000
	1"-8	1 5/8"	59/64"	250	1	90098A135	00000


	316 Stainless Steel



			3/8"-16	11/16"	13/32"	250	1	94530A113	0000


			1/2"-13	7/8"	17/32"	250	1	94530A115	0000
			5/8"-11	1 1/16"	39/64"	250	1	94530A117	0000
			3/4"-10	1 1/4"	45/64"	250	1	94530A119	00000

Thin-Profile Flex-Top Locknuts for Heavy Vibration

About two-thirds the height of standard flex-top nuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The top section expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. As a result, they're suitable for use in equipment with constant, vigorous vibration, such as engines. These locknuts are reusable a handful of times, but the holding power decreases with each use.

Steel

These locknuts have equivalent strength to Grade 8 and Class 10 steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Cadmium-Plated Steel—These locknuts have good lubricity to thread on smoothly and ease installation. The plating also creates a barrier against rust that's comparable to zinc-yellow-chromate plating.

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Pkg. Qty.		Pkg.
Cadmium-Plated Steel



	6-32	5/16"	9/64"	25	94830A485	000000


	8-32	11/32"	3/16"	25	94830A490	00000
	10-24	3/8"	3/16"	25	94830A495	00000
	10-32	3/8"	3/16"	25	94830A505	00000
	1/4"-20	7/16"	7/32"	25	94830A510	00000
	1/4"-28	7/16"	7/32"	25	94830A515	00000
	5/16"-18	1/2"	17/64"	10	94830A520	0000
	5/16"-24	1/2"	17/64"	10	94830A525	0000
	3/8"-16	9/16"	9/32"	10	94830A530	00000
	3/8"-24	9/16"	9/32"	10	94830A535	00000
	7/16"-20	5/8"	21/64"	5	94830A540	0000


	1/2"-13	3/4"	21/64"	5	94830A545	0000
	1/2"-20	3/4"	21/64"	5	94830A550	0000
	5/8"-11	15/16"	13/32"	1	94830A560	0000
	5/8"-18	15/16"	13/32"	1	94830A565	0000
	3/4"-10	1 1/16"	27/64"	1	94830A570	0000
	3/4"-16	1 1/16"	27/64"	1	94830A436	0000
	7/8"-9	1 1/4"	31/64"	1	94830A120	00000
	1"-8	1 7/16"	37/64"	1	94830A038	0000
	1"-14	1 7/16"	37/64"	1	94830A438	0000
	1 1/4"-12	1 13/16"	49/64"	1	94830A122	00000


	1 1/2"-12	2 3/16"	57/64"	1	94830A123	00000


	Steel



			6-32	5/16"	9/64"	10	94830A124	0000


			8-32	11/32"	3/16"	10	94830A125	0000
			10-24	3/8"	3/16"	10	94830A126	0000
			10-32	3/8"	3/16"	10	94830A127	0000
			1/4"-20	7/16"	7/32"	10	94830A128	0000
			1/4"-28	7/16"	7/32"	10	94830A129	0000
			5/16"-18	1/2"	17/64"	5	94830A130	0000
			5/16"-24	1/2"	17/64"	5	94830A131	0000
			3/8"-16	9/16"	9/32"	5	94830A132	0000
			3/8"-24	9/16"	9/32"	5	94830A133	0000
			1/2"-13	3/4"	21/64"	1	94830A134	0000


			1/2"-20	3/4"	21/64"	1	94830A135	0000
			5/8"-11	15/16"	13/32"	1	94830A136	0000
			5/8"-18	15/16"	13/32"	1	94830A137	0000
			3/4"-10	1 1/16"	27/64"	1	94830A138	0000
			3/4"-16	1 1/16"	27/64"	1	94830A139	0000
			1"-14	1 7/16"	37/64"	1	94830A140	0000
			1 1/8"-12	1 5/8"	41/64"	1	94830A141	00000
			1 1/4"-12	1 13/16"	49/64"	1	94830A142	00000
			1 3/8"-12	1 15/16"	53/64"	1	94830A143	00000
			1 1/2"-12	2 3/16"	57/64"	1	94830A144	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.	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	6-32	5/16"	9/64"	10	94140A100	000000


	8-32	11/32"	3/16"	5	94140A103	00000
	10-24	3/8"	3/16"	5	94140A105	00000
	10-32	3/8"	3/16"	10	94140A107	00000
	1/4"-20	7/16"	7/32"	5	94140A131	00000
	1/4"-28	7/16"	7/32"	5	94140A109	00000
	5/16"-18	1/2"	17/64"	1	94140A139	0000
	5/16"-24	1/2"	17/64"	1	94140A143	0000
	3/8"-16	9/16"	9/32"	1	94140A147	0000
	3/8"-24	9/16"	9/32"	1	94140A151	0000
	1/2"-13	3/4"	21/64"	1	94140A155	00000


	1/2"-20	3/4"	21/64"	1	94140A159	00000
	5/8"-18	15/16"	13/32"	1	94140A162	00000
	3/4"-16	1 1/16"	27/64"	1	94140A163	00000
	7/8"-14	1 1/4"	31/64"	1	94140A164	00000

Thin-Heavy-Profile Flex-Top Locknuts for Heavy Vibration

About two-thirds the height of standard flex-top nuts and 10% wider, these fit in spaces with low clearance and handle heavier loads by distributing them over a larger area. Because of the thin profile, you can also use them as jam nuts by threading them against a hex nut to hold it in place. The top section expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. As a result, they're suitable for use in equipment with constant, vigorous vibration, such as engines. These locknuts are reusable a handful of times, but the holding power decreases with each use.

Steel

These locknuts have equivalent strength to Grade 8 and Class 10 steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

	Wd.	Ht.	Pkg. Qty.		Pkg.
Cadmium-Plated Steel



	1/4"-20	1/2"	7/32"	25	94828A410	000000


	5/16"-18	9/16"	17/64"	10	94828A420	00000
	3/8"-16	5/8"	9/32"	10	94828A425	00000
	7/16"-14	3/4"	21/64"	1	94828A430	0000
	1/2"-13	13/16"	21/64"	5	94828A435	00000
	5/8"-11	1"	13/32"	1	94828A440	0000
	3/4"-10	1 1/8"	27/64"	1	94828A036	00000
	7/8"-9	1 5/16"	31/64"	1	94828A037	00000
	1"-8	1 1/2"	37/64"	1	94828A038	00000

Thin-Profile Steel-Insert Locknuts for Extreme Vibration

About two-thirds the height of standard steel-insert locknuts, these fit in spaces with low clearance and offer the most secure hold of all our thin-profile locknuts. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The tab on the insert stops the nut from rotating, even under extreme vibration. These locknuts are ideal for equipment with constant motion or jarring starts and stops, including conveyors, shakers, and compactors. In fact, they're so secure, they can even fasten components on roller-coasters. You can reuse them once or twice, but their holding power decreases after the first use, so you should use a new locknut for the strongest possible hold.

High-Strength Steel

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Fastener Strength Grade/Class		Each
Steel



	1/2"-13	3/4"	13/32"	SAE Grade 8	90619A021	00000


	5/8"-11	15/16"	1/2"	SAE Grade 8	90619A151	0000
	3/4"-10	1 1/8"	9/16"	SAE Grade 8	90619A167	0000
	3/4"-16	1 1/8"	9/16"	SAE Grade 8	90619A036	00000
	7/8"-9	1 5/16"	21/32"	SAE Grade 8	90619A175	00000
	7/8"-14	1 5/16"	19/32"	SAE Grade 8	90619A037	00000
	1"-8	1 1/2"	3/4"	SAE Grade 8	90619A189	00000
	1 1/4"-7	1 7/8"	31/32"	SAE Grade 8	90619A213	00000
	1 1/2"-6	2 1/4"	1 1/16"	SAE Grade 8	90619A228	00000