M40 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



		M40 × 1.5 mm	Extra Fine	56	12	210	—	———	0	3552N41	000000	———	0	———	0


		M40 × 1.5 mm	Extra Fine	58	12	160	ISO 2982-2	5197N114	000000	———	0	5197N135	000000	5510N156	0000000

Bearing Nuts

Carbon Steel

Chamfered Face

Carbon Steel

Stepped 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.

Stepped Face—Use stepped-face bearing nuts with DIN 462 spring lock washers. You can also use them in pairs or with other bearing nuts. For the nut closer to the bearing, position the stepped face towards the bearing. All meet DIN standards for bearing lockout dimensions.

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

				M40 × 1.5 mm	Extra Fine	58	9	DIN 981, ISO 2982	DIN 5406	3554N19	00000	90391A119	00000	5510N184	0000000




						Stepped Face

						M40 × 1.5 mm	Extra Fine	62	12	DIN 1804	DIN 462	3564N25	00000	90407A128	0000	———	0

Metric Precision Lead Screws and Nuts

Pair with a motor in automated motion and positioning applications. A tight thread fit allows these lead screws and nuts to make accurate, repeatable starts and stops. Also known as single-start and self-locking lead screws and nuts, they have a single thread that runs the length of the screw. The nut travels only when the screw turns, so your system won’t unexpectedly move when the lead screw is at rest. To ensure compatibility, select components that have the same thread direction, size, and number of thread starts.

Lead Screws—Right-Hand Thread

1018 Low-Carbon Steel—Carbon steel lead screws and flanges have good machinability.

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

	Lg., mm	Thread Type	Speed Ratio	No. of Thread Starts	Travel Distance per Turn, mm	Accuracy for Travel Distance per Turn	Thread Fit	Hardness	Tensile Strength, psi	Specs. Met		Each
1018 Low-Carbon Steel



	M40 × 7 mm	1,000	Metric Trapezoidal	1:1	1	7	±0.15 mm/300 mm	Metric Trapezoidal Class 8e	Brinell 150	85,000	DIN 103	7549K85	0000000


	M40 × 7 mm	1,750	Metric Trapezoidal	1:1	1	7	±0.15 mm/300 mm	Metric Trapezoidal Class 8e	Brinell 150	70,000	DIN 103	7549K12	000000

Round Nuts—Right-Hand Thread

932 Bearing Bronze—932 bearing bronze and 673 bronze nuts are wear resistant. They have good machinability and fair corrosion resistance.

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

	Lg.	Dia.	Thread Type	Speed Ratio	No. of Thread Starts	Travel Distance per Turn, mm	Thread Fit	Hardness	Tensile Strength	Dynamic Thrust Load Cap., lb.	Specs. Met		Each
932 Bearing Bronze



	M40 × 7 mm	3"	2.5"	Metric Trapezoidal	1:1	1	7	Metric Trapezoidal Class 7H	Brinell 70	Not Rated	12,300	DIN 103	7549K43	000000

Externally Threaded Nuts—Right-Hand Thread

Image of Product. Front orientation. Contains Annotated. Precision Lead Screws and Nuts. Metric Precision Lead Screws and Nuts, Externally Threaded Nuts—Right-Hand Thread.

Manganese Bronze—Manganese bronze nuts have good strength and wear resistance.

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

								External Thread
	Thread Size	Lg.	Dia.	Thread Type	Speed Ratio	No. of Thread Starts	Travel Distance per Turn, mm	Size	Lg.	Thread Fit	Hardness	Tensile Strength, psi	Dynamic Thrust Load Cap., lb.	Specs. Met		Each
Manganese Bronze



		M40 × 7 mm	2 19/64"	2.125"	Metric Trapezoidal	1:1	1	7	1 31/32"-18	13/16"	Metric Trapezoidal Class 7H	Brinell 126	75,000	12,300	DIN 103	7549K95	0000000

Flange Nuts—Right-Hand Thread

Manganese Bronze—Manganese bronze nuts have good strength and wear resistance.

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

				Flange
	Thread Size	Lg.	Dia.	Dia.	Thk.	Thread Type	Speed Ratio	Bolt Circle Dia.	No. of Thread Starts	Travel Distance per Turn, mm	Thread Fit	Hardness	Tensile Strength	Dynamic Thrust Load Cap., lb.	No. of Mounting Holes	Specs. Met		Each
Manganese Bronze



		M40 × 7 mm	2 19/64"	2.125"	4 13/64"	53/64"	Metric Trapezoidal	1:1	3 7/16"	1	7	Metric Trapezoidal Class 7H	Brinell 126	Not Rated	12,300	4	DIN 103	7549K27	0000000

Metric Lead Screws and Nuts

Found in hand-powered clamps, vises, grates, doors, and work tables, lead screws and nuts have broad, square threads that are well suited for quick assembly, high clamping forces, and lifting and lowering heavy objects. To ensure compatibility, please select components that have the same thread direction, size, and number of thread starts. Class 7e and 7H components are compatible.

Lead Screws—Right-Hand Thread

Black-Oxide Carbon Steel—Black-oxide carbon steel components have mild corrosion resistance.

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

	Thread Type	Lg., mm	No. of Thread Starts	Speed Ratio	Travel Distance per Turn, mm	Thread Fit	Fastener Strength Grade/Class	Hardness	Tensile Strength	Specs. Met		Each
Black-Oxide Carbon Steel



	M40 × 7 mm	Metric Trapezoidal	1,000	1	1:1	7	Metric Trapezoidal Class 7e	SAE Grade 2	Not Rated	Not Rated	ASTM A108, ASTM A193, DIN 103	97048A747	0000000


	M40 × 7 mm	Metric Trapezoidal	2,000	1	1:1	7	Metric Trapezoidal Class 7e	SAE Grade 2	Rockwell B72	Not Rated	ASTM A108	97048A739	000000

Flange Nuts—Right-Hand Thread

Flange nuts move objects along the length of a lead screw. They have a wide machinable flange for custom mounting.

932 Bearing Bronze—932 bearing bronze components are more wear resistant than brass components. They have good machinability and fair corrosion resistance.

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

					Flange, mm
	Thread Size	Thread Type	Ht., mm	Dia., mm	Dia.	Thk.	No. of Thread Starts	Speed Ratio	Travel Distance per Turn, mm	Thread Fit	Hardness	Tensile Strength		Each
932 Bearing Bronze



		M40 × 7 mm	Metric Trapezoidal	66	63	98	16	1	1:1	7	Metric Trapezoidal Class 7H	Not Rated	Not Rated	94353A326	0000000

Hex Nuts—Right-Hand Thread

Hex nuts fasten and position lead screw components.

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

	Thread Type	Ht., mm	Wd., mm	No. of Thread Starts	Speed Ratio	Travel Distance per Turn, mm	Thread Fit	Fastener Strength Grade/Class	Hardness	Tensile Strength		Each
Carbon Steel



	M40 × 7 mm	Metric Trapezoidal	39.9	60.33	1	1:1	7	Metric Trapezoidal Class 7H	SAE Grade 2	Not Rated	Not Rated	94353A400	000000

Threaded Air-Powered Hold-Down Fixture Clamps for Welding


Rubber Holding Screw Tip	Clamping Arm Adapter

Screw these clamps directly into a tapped hole and use air pressure to quickly and consistently clamp and release parts when welding. Compact and lightweight, these clamps are easy to move and reposition when welding. They’re also known as swing clamps. Connect these clamps to a control valve and air line. When pressure is applied, the arm on these clamps rotates 90° into position over your workpiece before clamping down. When pressure is released, the arm rises and rotates out of the way, so you can load or unload parts.

Rubber Holding Screw Tip—Clamps with a rubber-tipped holding screw are nonmarring. Their tip is removable.

Replacement Arms—Replacement arms (sold separately) do not include a holding screw. Extended arms (sold separately) give your clamp a longer reach than standard arms. However, you’ll have to use lower pressure, which means the actual clamping force will be lower than the clamp’s listed rating.

Arm Adapters—Add an arm adapter to mount your own custom-machined arm.

Clamps																Replacement Arms		Arm Adapters
					Body				Holding Screw		Female Air Inlet and Outlet
Max. Clamping Clearance	Vert. Travel During Rotation	Max. Clamping Stroke	Holding Cap., lb.	Reach Lg.	Thread Size	Thread Lg.	Sensor Ready	Overall Ht.	Thread Size	Tip Material	Thread Size	Thread Type	Material		Each		Each		Each







			90° Clockwise Rotation

			4"	1 3/32"	17/32"	35	1 15/16"	M40 × 1.5 mm	1 11/16"	Not Sensor Ready	4 5/8"	M6 × 1 mm	Rubber	M5 × 0.8 mm	Metric	Aluminum	9986N11	0000000	9986N17	000000	9986N18	000000




					90° Counterclockwise Rotation

					4"	1 3/32"	17/32"	35	1 15/16"	M40 × 1.5 mm	1 11/16"	Not Sensor Ready	4 5/8"	M6 × 1 mm	Rubber	M5 × 0.8 mm	Metric	Aluminum	9986N13	000000	9986N17	00000	9986N18	00000

Conduit Locknuts

Secure threaded conduit fittings to knockouts. These locknuts keep fittings from shifting, so connections stay stable and wiring is protected inside electrical boxes or enclosures.

For Metal and Plastic Fittings

304 Stainless Steel—The choice for wet and outdoor environments.

Nickel-Plated Brass—The plating enhances the corrosion resistance of brass, adding a durable protective finish.

	Each
Metric Thread







	304 Stainless Steel

	M40	—	7513K138	000000




			Nickel-Plated Brass

			M40	EN 60204	9147T22	00000

For Plastic Fittings

Nylon—Lightweight and chemical resistant, these fittings won't corrode.


Metric Thread







	Nylon

	M40	7877N114	00000


	M40	7877N135	0000

Fast-Travel Ball Screws and Nuts


	Flange Nut Ball Nuts 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



	M40	500	4	40	±0.05 mm/300 mm	35.4	Rockwell C56	95,000	32 to 150	4566N201	0000000


	M40	1,000	4	40	±0.05 mm/300 mm	35.4	Rockwell C56	95,000	32 to 150	4566N202	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	M40	101	66	106	18	4	40	85	Rockwell C56	9,550	0.07	32 to 150	4566N407	0000000

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

				M40 × 1.5 mm	Extra Fine	62	12	DIN 1816	3549N24	000000