M80 Nuts | McMaster-Carr

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.

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
	Size	Spacing	OD, mm	Wd., mm	Insert Max. Temp., ° F	Specs. Met		Each		Each		Each
Chamfered Face



		M80 × 2 mm	Extra Fine	105	16.5	210	—	———	0	3552N53	0000000	———	0


		M80 × 2 mm	Extra Fine	105	17	160	ISO 2982-2	5197N122	000000	———	0	5510N165	000000000

Bearing Nuts

Carbon Steel

Chamfered Face

Often paired with spring lock washers to strengthen their hold, these bearing nuts—also known as shaft nuts—keep vibration from shifting bearings, bushings, pulleys, and gears on your threaded shaft or spindle. They have slotted sides, so you can tighten and loosen them with a spanner wrench or spanner socket.

Carbon Steel—Carbon steel bearing nuts are strong and resist wear.

Chamfered Face—Chamfered-face bearing nuts weigh less and produce less heat than stepped-face nuts.

ISO 2982— Some chamfered-face bearing nuts meet ISO 2982 (formerly DIN 981), an international standard for bearing locknut dimensions. Their sizes correspond to SKF KM series. Use them with DIN 5406 spring lock washers.

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.

	Nuts								Bearing Lock Washers		Sockets
	Thread
	Size	Spacing	OD, mm	Wd., mm	Specs. Met	For Lock Washer Specs. Met		Each		Each		Each
Carbon Steel







				Chamfered Face

				M80 × 2 mm	Extra Fine	105	15	DIN 981, ISO 2982	DIN 5406	3554N28	000000	90391A128	00000	5510N193	000000000

Thin-Profile Bearing Nuts

Used in pairs or with another bearing nut, these thin-profile nuts—often called shaft nuts—hold bearings, bushings, pulleys, and gears in place on your threaded shaft or spindle. Threading two nuts tightly against each other makes it harder for vibration to loosen your assembly than if you used only one nut. For the nut closer to the bearing, position the stepped face towards the bearing. These thin-profile nuts have holes on the side, so you can tighten and loosen them with a pin spanner wrench. All meet DIN 1816, an international standard for bearing locknut dimensions.

Carbon Steel—Carbon steel bearing nuts are strong and resist wear.

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.

	Thread
	Size	Spacing	OD, mm	Wd., mm	Specs. Met		Each
Carbon Steel







				Stepped Face

				M80 × 2 mm	Extra Fine	115	16	DIN 1816	3549N39	000000

Spanner Sockets


Socket Shown With Wrench (Sold Separately)

4-Pin

For easy tightening and loosening, these sockets have pins that grip the slotted sides on bearing nuts. These sockets require less clearance around bearings than standard hook spanner wrenches, so they’re good in tight spaces. Use them with a square-drive wrench handle or a ratchet wrench; they’re not for use with impact wrenches.

							Clearance Dp., mm
	Drive Size, mm	Overall Lg., mm	OD, mm	For Nut Thread Size	For Bearing Nut Specs. Met	For Nut Dia., mm	Nut	Bolt	Material		Each
4-Pin Socket







				3/4" Square Drive

				105	127	121	M80	ISO 2982-2	105	—	81	Steel	5510N165	000000000




						1" Square Drive

						105	110	116	M80	DIN 981, ISO 2982	105	17	75	Steel	5510N193	00000000