M12 Locknuts | McMaster-Carr

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74 Products

Nylon-Insert Locknuts

Versatile yet economical, these are the most commonly used locknuts. 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

Image of Product. Front orientation. Locknuts. Nylon-Insert Locknuts.

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

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.

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



	M12 × 1.25 mm	19	12	Class 10	220	DIN 985, ISO 10511	10	94645A113	000000


	M12 × 1.5 mm	19	12	Class 10	220	DIN 985, ISO 10511	10	94645A229	0000
	M12 × 1.75 mm	19	12	Class 10	220	DIN 985	10	94645A230	00000


	Black-Corrosion-Resistant-Coated Steel



			M12 × 1.75 mm	19	12	Class 10	220	DIN 985	1	90237A160	0000

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-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.

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



	M12 × 1.75 mm	19	12	Class 8	220	DIN 985, ISO 10511	25	90576A817	000000


	Zinc-Plated Steel



			M12 × 1 mm	19	12	Class 8	220	DIN 985, ISO 10511	10	90576A137	0000


			M12 × 1.25 mm	19	12	Class 8	220	DIN 985, ISO 10511	25	90576A141	00000
			M12 × 1.5 mm	19	12	Class 8	220	DIN 985, ISO 10511	20	90576A144	00000
			M12 × 1.75 mm	19	12	Class 8	220	DIN 985, ISO 10511	50	90576A119	00000


			Black-Corrosion-Resistant-Coated Steel



					M12 × 1.75 mm	19	12	Class 8	220	DIN 985, ISO 10511	1	90819A116	0000

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.

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



	M12 × 1.75 mm	19	12	220	50	90631A117	000000

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.

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



	M12 × 1.5 mm	19	12	220	DIN 985	1	93625A130	00000


	M12 × 1.75 mm	19	12	220	DIN 985	10	93625A400	0000


	Black-Oxide 18-8 Stainless Steel



			M12 × 1.75 mm	19	12	240	DIN 985	5	93625A229	0000


			316 Stainless Steel



					M12 × 1.75 mm	19	12	220	DIN 985	10	94205A280	00000

Nylon-Insert Flange Nuts

A nylon insert grips the screw for a stronger hold than a serrated flange, without damaging threads or marring the surface of your material. However, the insert may become brittle if exposed to high temperatures. These nuts have a flange that distributes pressure evenly across the mounting surface, so you don't need a separate washer. They are ideal for securing screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts. You can reuse them a handful of times, but their holding power will decrease with each use. Also known as collar nuts.

Medium-Strength Steel

Image of Product. Front orientation. Flange Nuts. Nylon-Insert Flange Nuts.

Rated Grade 5, Grade F, or Class 8, these 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 Corrosion-Resistant-Coated Steel—Combines 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.

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Fastener Strength Grade/Class	Specs. Met	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M12 × 1.75 mm	18	16.1	26	1.8	Class 8	DIN 6926	250	25	92461A600	000000


		Black Corrosion-Resistant-Coated Steel



				M12 × 1.75 mm	18	16.1	26	1.8	Class 8	DIN 6926	250	5	97071A104	00000

High-Strength Steel

Rated Grade 8, Grade G, or Class 10, these are about 25% stronger than medium-strength steel nuts. They are commonly used to fasten components in valves, pumps, and motors. 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.

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Fastener Strength Grade/Class	Specs. Met	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M12 × 1.25 mm	18	16.1	26	1.8	Class 10	DIN 6926	250	1	90427A160	00000


		M12 × 1.5 mm	18	16.1	26	1.8	Class 10	DIN 6926	250	1	90427A170	0000
		M12 × 1.75 mm	18	16.1	26	1.8	Class 10	DIN 6926	250	5	90427A150	00000


		Zinc-Yellow-Chromate-Plated Steel



				M12 × 1.75 mm	18	16.1	26	1.8	Class 10	DIN 6926	250	25	99908A104	00000

Corrosion-Resistant Stainless Steel

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

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Specs. Met	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
18-8 Stainless Steel



		M12 × 1.75 mm	18	16.1	26	1.8	DIN 6926	250	1	94710A106	00000

Serrated Flange Nuts

Serrations bite into material for mild vibration resistance while the flange eliminates the need for a separate washer. These nuts are ideal for securing screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts. You can use them again and again without sacrificing strength. However, the serrations may mar the surface of your material. Also known as collar nuts.

Medium-Strength Steel

Image of Product. Bottom orientation. Flange Nuts. Serrated Flange Nuts.

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 that creates a finished look. They offer minimal corrosion resistance, so they're best for dry environments.

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

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M12 × 1.75 mm	18	12	26	1.8	Class 8	DIN 6923	25	96194A104	000000


		Zinc-Yellow-Chromate-Plated Steel



				M12 × 1.75 mm	18	12	26	1.8	Class 8	DIN 6923, ISO 4161	10	96194A160	00000


				Black-Oxide Steel



						M12 × 1.75 mm	18	12	26	1.8	Class 8	DIN 6923	25	94920A180	00000


						Steel



								M12 × 1.75 mm	18	12	26	1.8	Class 8	DIN 6923, ISO 4161	25	94920A101	00000

High-Strength Steel

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

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

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M12 × 1.75 mm	18	12	26	1.8	Class 10	DIN 6923	10	96595A104	00000


		Steel



				M12 × 1.75 mm	18	12	26	1.8	Class 10	DIN 6923	10	90716A104	00000

Corrosion-Resistant Stainless Steel

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

Highly Corrosion-Resistant 316 Stainless Steel—Our most corrosion-resistant flange nuts, these hold up in just about any environment, including harsh weather, salt water, and most chemicals.

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel



		M12 × 1.75 mm	18	12	26	2.19	DIN 6923	10	97400A104	00000


		Highly Corrosion-Resistant 316 Stainless Steel



				M12 × 1.75 mm	18	12	26	2.19	DIN 6923	5	92773A104	0000

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.

Low-Strength Steel

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

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



	M12 × 1.75 mm	18	10.3	245	ISO 10511	5	90453A117	00000

Top-Lock Distorted-Thread Locknuts

Irregularly shaped threads at the top of these locknuts grip the screw for a stronger hold than nylon-insert locknuts. Although the threads prevent the nut from backing out due to vibration, they also increase the effort to install and remove. To get these nuts off, you may need special tools, such as an impact wrench or propane torch. Nuts are not reusable.

High-Strength Steel

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

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

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



	M12 × 1.25 mm	19	12	Class 10	5	99183A490	000000


	M12 × 1.5 mm	19	12	Class 10	5	99183A810	00000
	M12 × 1.75 mm	19	12	Class 10	10	99183A280	0000


	Zinc-Plated Steel



			M12 × 1.25 mm	19	12	Class 10	25	99183A380	00000


			M12 × 1.5 mm	19	12	Class 10	10	99183A760	00000
			M12 × 1.75 mm	19	12	Class 10	25	99183A150	00000


			Black-Phosphate-Coated Steel



					M12 × 1.25 mm	19	12	Class 10	5	99183A570	00000


					M12 × 1.5 mm	19	12	Class 10	5	99183A580	00000
					M12 × 1.75 mm	19	12	Class 10	5	99183A590	0000

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., mm	Ht., mm	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M12 × 1.25 mm	19	12	Class 8	DIN 980V	25	93795A337	000000


	M12 × 1.5 mm	19	12	Class 8	DIN 980V	10	93795A334	00000
	M12 × 1.75 mm	19	12	Class 8	DIN 980V	25	93795A250	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., mm	Ht., mm	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M12 × 1.75 mm	19	12	DIN 980, ISO 7042	1	90045A121	00000

High-Profile Nylon-Insert Locknuts

Slightly taller than standard-profile locknuts, these have a larger gripping area so your wrench or socket won't slip off as you tighten them. They're often used in vehicles and machinery where fasteners can be difficult to reach. 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

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

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



	M12 × 1.75 mm	19	14	Class 10	220	DIN 982	10	97260A104	000000

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



	M12 × 1.75 mm	19	14	Class 8	220	DIN 982, ISO 7040	25	90576A829	000000


	Zinc-Plated Steel



			M12 × 1.75 mm	19	14	Class 8	220	DIN 982, ISO 7040	25	97131A160	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.

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



	M12 × 1.75 mm	19	14	220	DIN 982	5	93625A116	00000


	316 Stainless Steel



			M12 × 1.75 mm	19	14	220	DIN 982	5	94205A156	00000

Distorted-Thread Flange Nuts

The strongest hold of all the flange nuts we offer, these have irregularly shaped threads that grip the screw to resist loosening. The threads prevent the nut from backing out due to high vibration, but they also increase the effort to install and remove. To get these nuts off, you may need special tools, such as an impact wrench or propane torch, so they are not reusable. Nuts have a flange that distributes pressure evenly across the mounting surface without the need for a separate washer. They are ideal for securing screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts. Also known as collar nuts.

Medium-Strength Steel

Image of Product. Bottom orientation. Flange Nuts. Distorted-Thread Flange Nuts.

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

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M12 × 1.75 mm	18	13.8	26	1.8	Class 8	DIN 6927	25	90426A140	000000

High-Strength Steel

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

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M12 × 1.75 mm	18	13.8	26	1.8	Class 10	DIN 6927, EN 1664, ISO 7044	10	3528N14	000000


		Black-Oxide Steel



				M12 × 1.75 mm	18	13.8	26	1.8	Class 10	DIN 6927, EN 1664, ISO 7044	10	3528N24	0000

Spring-Stop Locknuts

These locknuts withstand heavy vibration similar to distorted-thread nuts, and you can use them over and over. The prongs at the top bend when tightened to create tension for a secure hold. As you remove the locknut, the prongs spring back to their original shape, so you can install the nut again without losing holding power. Also known as Fuji locknuts.

Low-Strength Steel

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

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



	M12 × 1.25 mm	17	10.4	Class 6	1	90508A160	00000

Steel-Insert Locknuts for Extreme Vibration

The most secure hold of all the locknuts we offer. 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 that they're even used to fasten components on roller coasters. These locknuts are also reusable, but their holding power decreases after the first use, so you should use a new nut for the strongest possible hold.

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.

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

	Wd., mm	Ht., mm	Fastener Strength Grade/Class		Each
Steel



	M12 × 1.75 mm	19	11.7	Class 8	93520A205	00000

Center-Lock Distorted-Thread Locknuts

Also known as reversible locknuts, these thread on from either side, so you don't have to worry about fastening them incorrectly and damaging your screw. The irregularly shaped threads in the middle grip the screw for a stronger hold than nylon-insert locknuts. Although the threads prevent the nut from backing out due to vibration, they also increase the effort to install and remove. To get these nuts off, you may need special tools, such as an impact wrench or propane torch. Nuts are not reusable.

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



	M12 × 1.25 mm	19	10	Class 8	5	92048A210	000000


	M12 × 1.5 mm	19	10	Class 8	5	92048A220	00000
	M12 × 1.75 mm	19	10	Class 8	5	92048A190	0000

Flex-Top Locknuts for Heavy Vibration

The top section of these nuts expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. They’re often used 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.

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.

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.

	Wd., mm	Ht., mm	Pkg. Qty.		Pkg.
Black-Oxide Steel



	M12 × 1.75 mm	19	15.6	1	94235A114	00000


	Cadmium-Plated Steel



			M12 × 1.75 mm	19	15.6	1	94235A120	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., mm	Ht., mm	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M12 × 1.75 mm	19	15.6	1	94560A120	000000


	316 Stainless Steel



			M12 × 1.75 mm	19	15.6	1	94560A180	00000

Locknuts with Spring-Lock Washer

The curved, spring-like washer grips surfaces more tightly than tooth-lock washers for better vibration resistance. These locknuts also install just as quickly since you can twist them into place by hand. Once the nut is against your material, tighten it down with a wrench or socket. The washer's smooth edges won't mar the surface like teeth can. As long as the washer stays intact, you can reuse these locknuts.

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



	M12 × 1.75 mm	19	13.8	Class 8	25.5	25	91270A360	000000

Bearing Locknuts

Carbon Steel

With a nylon insert that grips your threaded shaft or spindle without damaging its threads, these locknuts—also called shaft nuts—hold bearings, bushings, gears, and pulleys prone to vibration tightly in place. They come as one piece, so you can easily clamp them onto your shaft or spindle. But, since they aren’t made entirely of metal, they don’t stand up to heat as well as all-metal locknuts. Slots in their sides mean you can tighten and loosen them with a spanner wrench or spanner socket. Their face is also chamfered to help keep the size and weight of your assembly at a minimum. All meet international standards for bearing locknut dimensions.

Zinc-Plated Carbon Steel—Zinc-plated carbon steel locknuts resist rusting from some moisture, but you shouldn’t use them with salt water or chemicals. They are strong and resist wear, though they don’t stand up to corrosion as well as 303 stainless steel locknuts.

Carbon Steel—All carbon steel locknuts are strong and resist wear, though they don’t stand up to corrosion as well as 303 stainless steel locknuts.

303 Stainless Steel—303 stainless steel locknuts resist corrosion better than carbon steel locknuts but aren’t as strong. They withstand washdowns and chemicals.

Thread Spacing—When choosing your thread spacing, consider the precision of your application. The finer the threads, the more control you have when making adjustments.

	Locknuts												Sockets
	Thread						Carbon Steel		Zinc-Plated Carbon Steel		303 Stainless Steel
	Size	Spacing	OD, mm	Wd., mm	Insert Max. Temp., ° F	Specs. Met		Each		Each		Each		Each
Chamfered Face



		M12 × 1 mm	Extra Fine	21	7.5	210	—	———	0	3552N14	000000	———	0	———	0


		M12 × 1 mm	Extra Fine	22	8	160	ISO 2982-2	6343K33	000000	———	0	6343K95	000000	5510N145	0000000
		M12 × 1.5 mm	Fine	21	9	210	—	———	0	3552N15	00000	———	0	———	0

Locknuts for use with Cotter Pins

Use these locknuts to secure rotating parts subjected to mild vibration, such as the wheels on carts and hand trucks. They’re not recommended for use on parts exposed to high vibration because the pin can shear under prolonged stress. These nuts are reusable, but you'll need a new cotter pin (not included) with each use.

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.

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

	Wd., mm	Ht., mm	Fastener Strength Grade/Class	For Cotter Pin Dia., mm	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M12 × 1.5 mm	19	15	Class 8	3.2	DIN 935	5	93760A126	00000


	M12 × 1.75 mm	19	15	Class 8	3.2	DIN 935	5	93760A317	0000


	Steel



			M12 × 1.5 mm	19	15	Class 8	3.2	DIN 935	10	93760A131	0000

Weld Locknuts

Prevent screws from backing out under heavy vibration. These nuts have distorted threads that grip screws tightly. Three evenly spaced projections concentrate heat away from the threads to prevent them from deforming and create consistent welds. These nuts also have a collar pilot that guides the nut into the hole, holds it in place while welding, and protects the threads from weld spatter.

Use Grade 2 or Class 6 screws to avoid stripping threads during installation. Distorted threads require high torque for fastening and unfastening, so you may need an impact wrench to remove screws.

Steel—Best for dry environments since moisture will cause them to rust. Made of uncoated steel, these nuts require minimal prep. Weld them to uncoated steel surfaces.

				Collar, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Ht.	For Hole Dia., mm	Pkg. Qty.		Pkg.
Steel



		M12 × 1.75 mm	20.6	9.4	15.9	1.26	15.9	50	90744A340	000000


		M12 × 1.75 mm	21	9.7	16.1	1.8	16.1	10	90744A160	0000

Cap Nuts with Threadlocker

These nuts not only conceal and protect protruding screw threads, they also resist loosening from mild vibration. They have a nylon patch bonded to their threads that grips screws for a tighter hold than standard cap nuts. They’re reusable a handful of times, but the patch’s holding power decreases with each use. Also known as acorn nuts, they have a smooth, rounded head that creates a finished look.

Stainless Steel

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

	Thread Dp., mm	Wd., mm	Ht., mm	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M12 × 1.75 mm	12.2	19	22	DIN 1587	1	90428A150	000000

Nylon-Insert Cap Nuts

Get the protection of a cap nut with the vibration resistance of a locknut. These nuts not only conceal protruding screw threads, they also have a nylon insert that grips the screw to prevent loosening from moderate vibration. However, the insert may become brittle if exposed to high temperatures. Nuts are reusable a handful of times, but their holding power decreases with each use.

Low-Strength Steel

Rated Grade 2, Class 6, or lower, these nuts 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.

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



	M12 × 1.75 mm	8.3	18	23	Class 6	DIN 986	245	5	90582A116	00000