M15 Fasteners | 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.

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



		M15 × 1 mm	Extra Fine	24	8.5	210	—	———	0	0000000	000000	———	0	———	0


		M15 × 1 mm	Extra Fine	25	8.5	160	ISO 2982-2	0000000	000000	———	0	0000000	000000	00000000	0000000

Fast-Travel Ball Screws and Nuts


	Ball Nuts Flange Nut Style E

Multiple thread channels (also known as thread starts) create faster linear travel than ball screws with a single thread start. Internal ball bearings provide smooth low-friction travel in applications that require high speeds, accurate positioning, and repeatable movement. To ensure compatibility, select components that have the same thread size and number of thread starts. Ball nuts are furnished with a tube to keep ball bearings in place. Do not remove the tube until you are ready to install the nuts onto the screws.

Ball Screws—Right-Hand Threaded

Carbon Steel—Carbon steel ball screws and nuts are case hardened, so they resist wear better than standard carbon steel. However, they are less corrosion resistant than black-oxide alloy steel screws and nuts.

Travel Distance per Turn—Travel distance per turn, also known as screw lead, is the distance a ball nut moves with one revolution of the ball screw.

Root Diameter—Root diameter indicates the diameter the ball screw will be after machining away the threads.

	Lg., mm	No. of Thread Starts	Travel Distance per Turn, mm	Accuracy for Travel Distance per Turn	Root Dia., mm	Hardness	Tensile Strength, psi	Temp. Range, ° F		Each
Carbon Steel



	M15	500	4	16	±0.05 mm/300 mm	12.9	Rockwell C56	95,000	32 to 150	00000000	000000


	M15	500	4	20	±0.05 mm/300 mm	12.3	Rockwell C56	95,000	32 to 150	00000000	000000
	M15	1,000	4	16	±0.05 mm/300 mm	12.9	Rockwell C56	95,000	32 to 150	00000000	000000
	M15	1,000	4	20	±0.05 mm/300 mm	12.3	Rockwell C56	95,000	32 to 150	00000000	000000

Flange Ball Nuts—Right-Hand Threaded

Style E

Image of Attribute. Front orientation. Contains Annotated. Fast-Travel Ball Screws and Nuts.

Travel Distance per Turn—Travel distance per turn, also known as screw lead, is the distance a ball nut moves with one revolution of the ball screw.

					Flange, mm
	Style	Thread Size	Lg., mm	Dia., mm	Dia.	Thk.	No. of Thread Starts	Travel Distance per Turn, mm	Bolt Circle Dia., mm	Hardness	Dynamic Thrust Load Cap., lb.	Max. Backlash, mm	Temp. Range, ° F		Each
Carbon Steel



		E	M15	56	33	57	10	4	20	45	Rockwell C56	2,250	0.04	32 to 150	00000000	0000000


		E	M15	61	27	48	10	4	16	38	Rockwell C56	2,200	0.04	32 to 150	00000000	000000

Roller Screws and Nuts

Precision ground to create more points of contact, these roller screws and nuts are highly accurate and handle much higher loads than ball screws and nuts of the same size. They're most traditionally used to replace hydraulics in linear actuators but can also be used in place of ball and lead screw assemblies because of their high load capacity and precise motion control. In fact, they're almost four times more accurate than our most accurate ball and lead screws. They also last longer than ball screw nuts in systems with lower loads and can handle higher shock loads. However, because they have more contact points, they’re slightly less efficient than ball screws. To ensure compatibility, select components that have the same thread direction and size.

Roller Screws—Right-Hand Partially Threaded

Roller screws are made of hardened steel for strength and durability.

Travel Distance per Turn—Travel distance per turn, also known as screw lead, is the distance a roller nut moves with one revolution of the roller screw.

	Lg., mm	No. of Thread Starts	Travel Distance per Turn, mm	Accuracy for Travel Distance per Turn	Min. Thread Lg., mm	Root Dia., mm	Hardness	Tensile Strength, psi		Each
Alloy Steel



	M15	642	5	4	±0.023 mm/300 mm	522	14.59	Rockwell C60	105,000	0000000	000000000


	M15	642	5	5	±0.023 mm/300 mm	522	14.44	Rockwell C60	105,000	0000000	00000000

Round Nuts—Right-Hand Thread

Image of Product. Front orientation. Roller Screws and Nuts. Nuts.

Travel Distance per Turn—Travel distance per turn, also known as screw lead, is the distance a roller nut moves with one revolution of the roller screw.

						Keyway, mm
	Thread Size	Lg., mm	Dia., mm	No. of Thread Starts	Travel Distance per Turn, mm	Wd.	Dp.	Hardness	Dynamic Thrust Load Cap., lb.	Max. Backlash, mm	Temp. Range, ° F	Lubrication		Each
Alloy Steel



		M15	45	35	5	4	4	14	Rockwell C60	9,230	0.03	-40 to 350	Required	0000000	000000000


		M15	45	35	5	5	4	14	Rockwell C60	12,000	0.03	-40 to 350	Required	0000000	00000000

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

				M15 × 1 mm	Extra Fine	25	5	DIN 981, ISO 2982	DIN 5406	0000000	00000	000000000	00000	00000000	0000000

End Supports for Ball Screws and Precision Lead Screws

A set of ball bearings reduces friction and secures the end of a ball or lead screw. Note: The end of your ball or lead screw must be machined before installing it into an end support.

For Combined Radial and Thrust Loads About For Combined Radial and Thrust Loads

Image of Product. Front orientation. Contains Annotated. End Supports for Ball Screws and Precision Lead Screws. For Combined Radial and Thrust Loads.

End supports for combined radial and thrust loads handle radial loads (perpendicular to the lead screw) and thrust loads (parallel to the lead screw).

						Combined Load Cap., lbf			Top Mounting Holes, mm
	ID, mm	Ht., mm	Ctr. Ht., mm	Wd., mm	Dp., mm	Static	Dynamic	No. of Mounting Holes	Dia.	Ctr.-to-Ctr. Wd.	Temp. Range, ° F		Each
Carbon Steel



		15	48	28	70	38	890	1,700	4	6.6	54	0 to 160	0000000	0000000