M8 Locknuts | McMaster-Carr

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71 Products

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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 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—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.

Large Pack—Priced at least 30% lower per locknut than small packs.

							Small Pack			Large Pack
	Thread Size	Wd., mm	Ht., mm	Fastener Strength Grade/Class	Insert Max. Temp., ° F	Certificate Type	Pkg. Qty.		Pkg.	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 × 1.25 mm	13	8	Class 10	185	Material Certificate	50	94645A210	000000	1,000	94645A209	0000000


		M8 × 1 mm	13	8	Class 10	185	Material Certificate	10	94645A111	00000	—	———	0


		Black-Corrosion-Resistant-Coated Steel



				M8 × 1.25 mm	13	8	Class 10	185	—	5	90237A140	00000	—	———	0

Medium-Strength Steel

These Grade 5, Grade C, 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.

Large Pack—Priced at least 30% lower per locknut than small packs.

							Small Pack			Large Pack
	Thread Size	Wd., mm	Ht., mm	Fastener Strength Grade/Class	Insert Max. Temp., ° F	Certificate Type	Pkg. Qty.		Pkg.	Pkg. Qty.		Pkg.
Zinc-Yellow-Chromate-Plated Steel



		M8 × 1.25 mm	13	8	Class 8	185	—	100	90576A815	000000	—	———	0


		M8 × 1.25 mm	13	8	Class 8	185	Material Certificate	—	———	0	2,000	90576A133	0000000


		Zinc-Plated Steel



				M8 × 1.25 mm	13	8	Class 8	185	Material Certificate	100	90576A117	00000	—	———	0


				M8 × 1 mm	13	8	Class 8	185	—	25	90576A116	0000	—	———	0


				Black-Corrosion-Resistant-Coated Steel



						M8 × 1.25 mm	13	8	Class 8	185	—	5	90819A114	00000	—	———	0

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



	M8 × 1.25 mm	13	8	185	100	90631A115	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.

Large Pack—Priced at least 30% lower per locknut than small packs.

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

						Small Pack			Large Pack
	Thread Size	Wd., mm	Ht., mm	Insert Max. Temp., ° F	Certificate Type	Pkg. Qty.		Pkg.	Pkg. Qty.		Pkg.
18-8 Stainless Steel



		M8 × 1.25 mm	13	8	185	Material Certificate	50	93625A300	000000	1,000	93625A125	0000000


		M8 × 1 mm	13	8	185	Material Certificate	5	93625A110	00000	—	———	0


		Black-Oxide 18-8 Stainless Steel



				M8 × 1.25 mm	13	8	185	Material Certificate	10	93625A227	0000	200	93625A134	000000


				316 Stainless Steel



						M8 × 1.25 mm	13	8	185	Material Certificate	25	94205A260	0000	—	———	0

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.

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-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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 × 1.25 mm	13	8	17.9	1.2	Class 8	DIN 6923, ISO 4161	—	100	96194A102	000000


		M8 × 1 mm	13	8	17.9	1.2	Class 8	DIN 6923	—	100	96194A107	00000


		Zinc-Yellow-Chromate-Plated Steel



				M8 × 1.25 mm	13	8	17.9	1.2	Class 8	DIN 6923, ISO 4161	Material Certificate	50	96194A140	00000


				Black-Oxide Steel



						M8 × 1.25 mm	13	8	17.9	1.2	Class 8	DIN 6923	Material Certificate	100	94920A150	00000


						M8 × 1 mm	13	8	17.9	1.2	Class 8	DIN 6923	—	100	94920A140	00000


						Steel



								M8 × 1.25 mm	13	7	18.25	2.6	Class 8	—	—	25	94920A500	00000


								M8 × 1 mm	13	8	17.9	1.2	Class 8	DIN 6923	—	100	94920A106	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.

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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 × 1.25 mm	13	8	17.9	1.2	Class 10	DIN 6923	Material Certificate	50	96595A102	000000


		Steel



				M8 × 1.25 mm	13	8	17.9	1.2	Class 10	DIN 6923	—	50	90716A102	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	Certificate Type	Pkg. Qty.		Pkg.
18-8 Stainless Steel



		M8 × 1.25 mm	13	8	17.9	1.3	DIN 6923	—	25	97400A102	00000


		Highly Corrosion-Resistant 316 Stainless Steel



				M8 × 1.25 mm	13	8	17.9	1.3	DIN 6923	Material Certificate	10	92773A102	0000

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.

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

Black Corrosion-Resistant-Coated 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	Certificate Type	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 × 1.25 mm	13	11.1	17.9	1.2	Class 8	DIN 6926	Material Certificate	250	100	92461A400	000000


		Black Corrosion-Resistant-Coated Steel



				M8 × 1.25 mm	13	11.1	17.9	1.2	Class 8	DIN 6926	—	250	5	97071A103	0000

High-Strength Steel

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	Certificate Type	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 × 1.25 mm	13	11.1	17.9	1.2	Class 10	DIN 6926	Material Certificate	250	10	90427A120	00000


		Zinc-Yellow-Chromate-Plated Steel



				M8 × 1.25 mm	13	11	17.9	1.2	Class 10	DIN 6926	Material Certificate	250	50	99908A102	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.

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



		M8 × 1.25 mm	13	11.1	17.9	1.2	DIN 6926	Material Certificate	250	5	94710A104	000000

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.

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

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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M8 × 1.25 mm	13	6.8	245	Material Certificate	5	90453A115	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

Rated Grade 8 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-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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Yellow-Chromate-Plated Steel



	M8 × 1.25 mm	13	8	Class 10	—	50	99183A260	000000


	M8 × 1 mm	13	8	Class 10	—	10	99183A790	0000


	Zinc-Plated Steel



			M8 × 1.25 mm	13	8	Class 10	—	50	99183A130	00000


			M8 × 1 mm	13	8	Class 10	Material Certificate	50	99183A360	00000


			Black-Phosphate-Coated Steel



					M8 × 1.25 mm	13	8	Class 10	—	25	99183A540	00000


					M8 × 1 mm	13	8	Class 10	—	10	99183A530	0000

Medium-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



	M8 × 1.25 mm	13	8	Class 8	50	93795A230	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	Certificate Type	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M8 × 1.25 mm	13	6.4	Material Certificate	10	90045A115	000000


	M8 × 1 mm	13	6.4	—	5	90045A116	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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 × 1.25 mm	13	9.4	17.9	1.2	Class 8	DIN 6927	Material Certificate	50	90426A120	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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 × 1.25 mm	13	9.4	17.9	1.2	Class 10	DIN 6927, EN 1664, ISO 7044	—	25	3528N12	000000


		Black-Oxide Steel



				M8 × 1.25 mm	13	9.4	17.9	1.2	Class 10	DIN 6927, EN 1664, ISO 7044	Material Certificate	10	3528N22	0000

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

Rated Grade 8 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.

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



	M8 × 1.25 mm	13	9.5	Class 10	220	25	97260A102	00000

Medium-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	Pkg. Qty.		Pkg.
Zinc-Yellow-Chromate-Plated Steel



	M8 × 1.25 mm	13	9.5	Class 8	220	100	90576A827	000000


	Zinc-Plated Steel



			M8 × 1.25 mm	13	9.5	Class 8	220	50	97131A140	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	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M8 × 1.25 mm	13	9.5	220	10	93625A114	00000


	316 Stainless Steel



			M8 × 1.25 mm	13	9.5	220	10	94205A154	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.

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

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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M8 × 1.25 mm	12	7.3	Class 6	Material Certificate	10	90508A130	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.

	Wd., mm	Ht., mm	Certificate Type	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M8 × 1.25 mm	13	7.2	Material Certificate	5	90543A130	000000

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.

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

Medium-Strength Steel

Image of Product. Front orientation. ZoomedIn view. Locknuts. Locknuts with External-Tooth Lock Washer.

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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M8 × 1.25 mm	13	8.5	Class 8	15.5	Material Certificate	25	93825A160	00000


	Black-Zinc-Plated Steel



			M8 × 1.25 mm	13	8.5	Class 8	15.5	Material Certificate	25	93825A250	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	Washer OD, mm	Certificate Type	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M8 × 1.25 mm	13	8.5	15.1	Material Certificate	5	90923A241	00000

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



	M8 × 1.25 mm	13	10.4	1	94235A112	00000


	Cadmium-Plated Steel



			M8 × 1.25 mm	13	10.4	1	94235A090	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	Certificate Type	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M8 × 1.25 mm	13	10.4	Material Certificate	1	94560A080	00000


	316 Stainless Steel



			M8 × 1.25 mm	13	10.4	—	1	94560A160	00000

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



		M8 × 1.25 mm	14.7	6.6	10.9	1	10.9	50	90744A320	000000


		M8 × 1.25 mm	15	7	11.1	1.8	11.1	10	90744A180	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.

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

Stainless Steel

Image of Product. Front orientation. Contains Annotated, Border. Cap Nuts. Cap Nuts with Threadlocker.

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	Certificate Type	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	M8 × 1.25 mm	8.2	13	15	DIN 1587	Material Certificate	5	90428A130	000000

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

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	For Cotter Pin Dia., mm	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M8 × 1.25 mm	13	9.5	Class 8	2	5	93760A222	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

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



	M8 × 1.25 mm	13	8.8	Class 8	18	50	91270A340	000000

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.

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

Medium-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	Certificate Type	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M8 × 1.25 mm	13	6.5	Class 8	Material Certificate	10	92048A140	000000


	M8 × 1 mm	13	6.5	Class 8	Material Certificate	10	92048A150	00000

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.

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

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	Certificate Type	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	M8 × 1.25 mm	5.2	13	14	Class 6	DIN 986	Material Certificate	245	25	90582A114	000000

Thick-Wall Highly Twist-Resistant Rivet Locknuts

Keep screws locked in place with nuts that won't budge. Irregularly shaped threads stop screws from loosening under vibration and the hex-shaped body holds the nut in place when turning screws. With thick walls that distribute heavy loads better than standard walls, these nuts are strong enough for heavy machinery such as forklifts. The screw-locking threads require high torque, so you may need an impact wrench to remove screws.

Install these nuts in a drilled or punched round hole using a rivet nut tool. Choose an air- or battery-powered tool for faster installation or to install many different nut sizes. Length is measured from under the flange.

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

							Flange, mm
	Thread Size	Wd. Across Flats, mm	For Material Thk., mm	Body Dia., mm	Lg., mm	Installed Lg., mm	Dia.	Thk.	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		M8 x 1.25 mm	11	0.8 to 4	10.98	19.6	13.6	16	1.5	10	92009A210	00000


		M8 x 1.25 mm	11	4 to 7	10.98	22.8	13.6	16	1.5	10	92009A220	0000

Steel Serrated-Flange Hex Head Screw and Nut Assortments


	Class 8.8

Stock up on fasteners in various sizes to create vibration-resistant joints. The screws and nuts in these assortments both have a flange with a serrated edge that grips your material to keep screws in place. The screws have a head with six flat sides to keep wrenches and sockets from slipping and rounding off the drive.

Head height includes the flange. Length is measured from under the flange.

Medium-Strength Fastener—Your go-to screws for fastening most machinery and equipment. They have tensile strengths from 90,000 to 120,000 psi.

Zinc-Plated Steel—A common choice for areas with occasional exposure to moisture.

	Serrated-Flange Hex Head Screws Included	Serrated Flange Nuts Included	Fastener Strength Grade/Class	Container Type		Each
Medium-Strength Zinc-Plated Steel



	475	M6 × 1 mm Thread: 12 mm, 16 mm, 20 mm, 25 mm, and 30 mm Lg. (145 Pieces) M8 × 1.25 mm Thread: 16 mm, 20 mm, 30 mm, and 40 mm Lg. (85 Pieces) M10 × 1.5 mm Thread: 20 mm, 25 mm, 30 mm, and 40 mm Lg. (75 Pieces)	M6 × 1 mm Thread (80 Pieces) M8 × 1.25 mm Thread (50 Pieces) M10 × 1.5 mm Thread (40 Pieces)	Class 8.8, Class 8	Metal Box	91638A114	0000000

Stainless Steel Serrated-Flange Hex Head Screw and Nut Assortments

Keep assorted corrosion-resistant fasteners on hand to create vibration-resistant joints. The screws and nuts in these assortments both have a flange with a serrated edge that grips your material to keep screws in place. The screws have a head with six flat sides to keep wrenches and sockets from slipping and rounding off the drive.

Head height includes the flange. Length is measured from under the flange.

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

	Serrated-Flange Hex Head Screws Included	Serrated Flange Nuts Included	Container Type		Each
18-8 Stainless Steel



	455	M6 × 1 mm Thread: 16 mm, 20 mm, 25 mm, 35 mm, and 50 mm Lg. (135 Pieces) M8 × 1.25 mm Thread: 16 mm, 20 mm, 30 mm, and 50 mm Lg. (85 Pieces) M10 × 1.5 mm Thread: 20 mm, 30 mm, 40 mm, and 50 mm Lg. (65 Pieces)	M6 × 1 mm Thread (80 Pieces) M8 × 1.25 mm Thread (50 Pieces) M10 × 1.5 mm Thread (40 Pieces)	Metal Box	91638A111	0000000