Metric Class 8 Nuts | McMaster-Carr

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76 Products

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


	M6 × 1 mm	10	7.5	ISO Class 8	1.6	DIN 935	5	000000000	00000
	M8 × 1.25 mm	13	9.5	ISO Class 8	2	DIN 935	5	000000000	0000
	M10 × 1.5 mm	17	12	ISO Class 8	2.5	DIN 935	5	000000000	0000
	M12 × 1.5 mm	19	15	ISO Class 8	3.2	DIN 935	5	000000000	0000
	M12 × 1.75 mm	19	15	ISO Class 8	3.2	DIN 935	5	000000000	0000
	M14 × 1.5 mm	22	16	ISO Class 8	3.2	DIN 935	1	000000000	0000
	M14 × 2 mm	22	16	ISO Class 8	3.2	DIN 935	1	000000000	0000
	M16 × 1.5 mm	24	19	ISO Class 8	4	DIN 935	10	000000000	00000
	M16 × 2 mm	24	19	ISO Class 8	4	DIN 935	5	000000000	0000
	M18 × 2.5 mm	27	21	ISO Class 8	4	DIN 935	1	000000000	0000
	M20 × 2.5 mm	30	22	ISO Class 8	4	DIN 935	5	000000000	00000
	M24 × 2 mm	36	27	ISO Class 8	5	DIN 935	1	000000000	0000
	M24 × 3 mm	36	27	ISO Class 8	5	DIN 935	1	000000000	0000
	M27 × 3 mm	41	30	ISO Class 8	5	DIN 935	1	000000000	00000
	M30 × 3.5 mm	46	33	ISO Class 8	6.3	DIN 935	1	000000000	00000

	Steel


			M12 × 1.5 mm	19	15	ISO Class 8	3.2	DIN 935	10	000000000	0000
			M14 × 1.5 mm	22	16	ISO Class 8	3.2	DIN 935	1	000000000	0000
			M14 × 2 mm	22	16	ISO Class 8	3.2	DIN 935	1	000000000	0000
			M16 × 1.5 mm	24	19	ISO Class 8	4	DIN 935	1	000000000	0000
			M16 × 2 mm	24	19	ISO Class 8	4	DIN 935	1	000000000	0000
			M18 × 2.5 mm	27	21	ISO Class 8	4	DIN 935	1	000000000	0000
			M20 × 2.5 mm	30	22	ISO Class 8	4	DIN 935	1	000000000	0000
			M24 × 3 mm	36	27	ISO Class 8	5	DIN 935	1	000000000	0000
			M30 × 3.5 mm	46	33	ISO Class 8	6.3	DIN 935	1	000000000	00000
			M36 × 3 mm	55	38	ISO Class 8	6.3	DIN 935	1	000000000	00000
			M36 × 4 mm	55	38	ISO Class 8	6.3	DIN 935	1	000000000	00000
			M42 × 4.5 mm	65	46	ISO Class 8	8	DIN 935	1	000000000	00000
			M48 × 5 mm	75	50	ISO Class 8	8	DIN 935	1	000000000	00000
			M56 × 5.5 mm	85	57	ISO Class 8	8	DIN 935	1	000000000	00000

Left-Hand-Thread Hex Nuts

These nuts tighten when turned to the left. Use them with left-hand rods and screws to prevent counterclockwise-moving parts from loosening.

Medium-Strength Steel

Image of Product. Front orientation. Contains Annotated, MultipleImages. Hex Nuts. Left-Hand-Thread Hex Nuts.

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


	M5 × 0.8 mm	8	4	ISO Class 8	DIN 934L	100	000000000	000000
	M6 × 1 mm	10	5	ISO Class 8	DIN 934L	100	000000000	00000
	M8 × 1.25 mm	13	6.5	ISO Class 8	DIN 934L	50	000000000	00000
	M10 × 1.5 mm	17	8	ISO Class 8	DIN 934L	25	000000000	00000
	M12 × 1.75 mm	19	10	ISO Class 8	DIN 934L	25	000000000	00000
	M14 × 2 mm	22	11	ISO Class 8	DIN 934L	10	000000000	00000
	M16 × 2 mm	24	13	ISO Class 8	DIN 934L	10	000000000	00000
	M20 × 2.5 mm	30	16	ISO Class 8	DIN 934L	5	000000000	00000
	M24 × 3 mm	36	19	ISO Class 8	DIN 934L	1	000000000	0000
	M30 × 3.5 mm	46	24	ISO Class 8	DIN 934L	1	000000000	0000
	M36 × 4 mm	55	29	ISO Class 8	DIN 934L	1	000000000	00000

Low-Strength Steel

Rated Grade 2, Class 6, or lower, these nuts are about half as strong as medium-strength nuts. They are suitable for light duty fastening applications, such as securing access panels. 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	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel


	M3 × 0.5 mm	5.5	2.4	ISO Class 5	DIN 934L	25	000000000	000000
	M4 × 0.7 mm	7	3.2	ISO Class 5	DIN 934L	25	000000000	0000

Wing Nuts


Style 1	Style 4

The easiest nuts to twist on and off by hand, these are commonly used to fasten parts that need to be frequently disassembled, such as access panels and covers. The wings give you more leverage than knurled-head nuts, so you can apply greater torque and achieve a tighter fit.

Steel

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

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





	Style 1
	M3 × 0.5 mm	19.5	10	8	ISO Class 5	—	25	000000000	00000
	M4 × 0.7 mm	17.6	8.6	8	ISO Class 5	DIN 315	50	000000000	00000
	M5 × 0.8 mm	22.5	11	10.3	ISO Class 5	DIN 315	25	000000000	0000
	M6 × 1 mm	27.8	13.6	12.7	ISO Class 5	DIN 315	25	000000000	0000
	M8 × 1.25 mm	30.3	14.8	13.8	ISO Class 5	DIN 315	20	000000000	0000
	M10 × 1.5 mm	36.2	17.7	16.5	ISO Class 5	DIN 315	10	000000000	0000
	M12 × 1.75 mm	49.4	24.1	22.5	ISO Class 5	DIN 315	5	000000000	0000



			Style 4
			M4 × 0.7 mm	20	10.5	8	ISO Class 5	DIN 315	10	000000000	0000
			M5 × 0.8 mm	26	13	11	ISO Class 5	DIN 315	10	000000000	0000
			M6 × 1 mm	33	17	13	ISO Class 5	DIN 315	10	000000000	0000
			M8 × 1.25 mm	39	20	16	ISO Class 5	DIN 315	5	000000000	0000
			M10 × 1.5 mm	51	25	20	ISO Class 5	DIN 315	5	000000000	00000
			M12 × 1.75 mm	65	33.5	23	ISO Class 5	DIN 315	1	000000000	0000
			M16 × 2 mm	73	37.5	29	ISO Class 5	DIN 315	1	000000000	00000

Low-Strength Steel Square Nuts

Large flat sides make these nuts easy to grip with a wrench and keep them from rotating in channels and square holes. About half the strength of medium-strength steel square nuts, use them in light duty fastening applications, such as securing access panels.

Black-Zinc-Plated Steel—Black-zinc-plated steel square nuts resist corrosion in wet environments and have a black finish that blends in with dark surfaces.

Steel—Steel square nuts are best for dry environments, since moisture will cause them to rust.

Zinc-Plated Steel—Zinc-plated steel square nuts resist corrosion in wet environments.

	Wd., mm	Ht., mm	Specs. Met	Pkg. Qty.		Pkg.
Steel—ISO Class 5


	M4 × 0.7 mm	7	3	DIN 557	50	000000000	00000
	M5 × 0.8 mm	8	4	DIN 557	50	000000000	00000
	M6 × 1 mm	10	5	DIN 557	25	000000000	0000
	M8 × 1.25 mm	13	6.5	DIN 557	25	000000000	0000
	M10 × 1.5 mm	17	8	DIN 557	10	000000000	0000
	M12 × 1.75 mm	19	10	DIN 557	5	000000000	0000

	Zinc-Plated Steel—ISO Class 5


			M4 × 0.7 mm	7	3.2	DIN 557	100	000000000	00000
			M5 × 0.8 mm	8	4	DIN 557	100	000000000	00000
			M6 × 1 mm	10	5	DIN 557	100	000000000	00000
			M8 × 1.25 mm	13	6.5	DIN 557	25	000000000	0000
			M10 × 1.5 mm	17	8	DIN 557	25	000000000	00000
			M12 × 1.75 mm	19	10	DIN 557	10	000000000	0000
			M16 × 2 mm	24	13	DIN 557	5	000000000	00000
			M20 × 2.5 mm	30	16	DIN 557	5	000000000	00000

			Black-Zinc-Plated Steel—ISO Class 5


					M4 × 0.7 mm	7	3	DIN 557	25	000000000	0000
					M5 × 0.8 mm	8	4	DIN 557	25	000000000	0000
					M6 × 1 mm	10	5	DIN 557	25	000000000	0000
					M8 × 1.25 mm	13	6.5	DIN 557	10	000000000	0000
					M10 × 1.5 mm	17	8	DIN 557	10	000000000	00000
					M16 × 2 mm	24	13	DIN 557	1	000000000	0000