M8 Lead Screws | McMaster-Carr

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18 Products

Metric Fast-Travel Ultra-Precision Lead Screws and Nuts


	Style A	Style B	Style E	Style F

Multiple thread channels (also known as thread starts) create faster linear travel than lead screws with a single thread start. Operating with less backlash (play) than Metric Precision Acme Lead Screws and Nuts, these lead screws and nuts provide increased nut life and more reliable movement in automated systems. To ensure compatibility, select components that have the same thread size and number of thread starts.

Lead Screw—Right-Hand Thread

4140 Alloy Steel—Alloy steel lead screws are hard and strong.

304 Stainless Steel—304 stainless steel lead screws have good 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., mm	Thread Type	Speed Ratio	No. of Thread Starts	Travel Distance per Turn, mm	Accuracy for Travel Distance per Turn	Hardness	Tensile Strength, psi		Each
4140 Alloy Steel



	M8 × 2 mm	200	Metric Rounded Trapezoidal	2:1	2	4	±0.089 mm/300 mm	Brinell 200	125,000	000000000	000000


	M8 × 2 mm	300	Metric Rounded Trapezoidal	2:1	2	4	±0.089 mm/300 mm	Brinell 200	125,000	000000000	00000


	304 Stainless Steel



			M8 × 2.5 mm	250	Metric Rounded Trapezoidal	4:1	4	10	±0.1 mm/300 mm	Brinell 160	72,000	0000000	00000


			M8 × 2.5 mm	500	Metric Rounded Trapezoidal	4:1	4	10	±0.1 mm/300 mm	Brinell 160	72,000	0000000	00000

Round Nuts—Right-Hand Thread

Style A

Acetal—Acetal nuts have good wear and 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 Size	Lg.	Dia.	Thread Type	Speed Ratio	No. of Thread Starts	Travel Distance per Turn, mm	Hardness	Tensile Strength, psi	Dynamic Thrust Load Cap.	Temp., ° F		Each
Acetal



	A	M8 × 2.5 mm	15/32"	0.709"	Metric Rounded Trapezoidal	4:1	4	10	Durometer 74D	10,000	Not Rated	-40 to 185	0000000	000000

Externally Threaded Nuts—Right-Hand Thread

Style B

Acetal—Acetal nuts have good wear and 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.

										External Thread
	Style	Thread Size	Lg.	Dia.	Hex Wd.	Thread Type	Speed Ratio	No. of Thread Starts	Travel Distance per Turn, mm	Size	Lg.	Hardness	Tensile Strength, psi	Dynamic Thrust Load Cap., lb.	Temp., ° F		Each
Acetal



		B	M8 × 2 mm	1"	0.548"	11/16"	Metric Rounded Trapezoidal	2:1	2	4	5/8"-18	1/4"	Not Rated	8,000	75	-40 to 185	000000000	000000

Flange Nuts—Right-Hand Thread


Style E	Style F

Style E

Style F

Acetal—Acetal nuts have good wear and 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
	Style	Thread Size	Lg.	Dia.	Dia.	Thk.	Thread Type	Speed Ratio	Bolt Circle Dia.	No. of Thread Starts	Travel Distance per Turn, mm	Hardness	Tensile Strength, psi	Dynamic Thrust Load Cap., lb.	No. of Mounting Holes	Temp., ° F		Each
Acetal



		E	M8 × 2 mm	3/4"	0.548"	1 1/8"	3/16"	Metric Rounded Trapezoidal	2:1	7/8"	2	4	Not Rated	8,000	75	3	-40 to 185	000000000	000000


		F	M8 × 2.5 mm	25/32"	0.787"	1 27/64"	5/16"	Metric Rounded Trapezoidal	4:1	1 7/64"	4	10	Durometer 74D	10,000	Not Rated	6	-40 to 185	0000000	00000

Metric Ultra-Precision Lead Screws and Nuts


	Style A	Style D

Operating with less backlash (play) than Metric Precision Acme Lead Screws and Nuts, these provide increased nut life and more reliable movement in automated systems. 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 size, thread type, thread size, thread pitch, and number of thread starts.

Lead Screw—Right-Hand Thread

4140 Alloy Steel—Alloy steel lead screws are hard and strong.

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	Hardness	Tensile Strength, psi		Each
4140 Alloy Steel



	M8 × 1.5 mm	100	Metric Rounded Trapezoidal	1:1	1	1.5	±0.089 mm/300 mm	Brinell 200	125,000	0000000	000000


	M8 × 1.5 mm	200	Metric Rounded Trapezoidal	1:1	1	1.5	±0.089 mm/300 mm	Brinell 200	125,000	0000000	00000
	M8 × 1.5 mm	300	Metric Rounded Trapezoidal	1:1	1	1.5	±0.089 mm/300 mm	Brinell 200	125,000	0000000	00000

Externally Threaded Nuts—Right-Hand Thread

Style A

Acetal—Acetal nuts have good wear and 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.

										External Thread
	Style	Thread Size	Lg.	Dia.	Hex Wd.	Thread Type	Speed Ratio	No. of Thread Starts	Travel Distance per Turn, mm	Size	Lg.	Hardness	Tensile Strength, psi	Dynamic Thrust Load Cap., lb.	Temp., ° F		Each
Acetal



		A	M8 × 1.5 mm	1"	0.548"	11/16"	Metric Rounded Trapezoidal	1:1	1	1.5	5/8"-18	1/4"	Not Rated	8,000	75	-40 to 185	0000000	000000

Flange Nuts—Right-Hand Thread


Style D	Style D

Acetal—Acetal nuts have good wear and 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
	Style	Thread Size	Lg.	Dia.	Dia.	Thk.	Thread Type	Speed Ratio	Bolt Circle Dia.	No. of Thread Starts	Travel Distance per Turn, mm	Hardness	Tensile Strength, psi	Dynamic Thrust Load Cap., lb.	No. of Mounting Holes	Temp., ° F		Each
Acetal



		D	M8 × 1.5 mm	3/4"	0.548"	1 1/8"	3/16"	Metric Rounded Trapezoidal	1:1	7/8"	1	1.5	Not Rated	8,000	75	3	-40 to 185	0000000	000000

Ball Screws and Nuts

Internal ball bearings provide smooth low-friction travel in applications that require high speeds, accurate positioning, and repeatable movement. Also known as single-start ball screws and nuts, they have a single thread that runs the length of the screw. They operate with more torque than fast-travel ball screws and nuts. To ensure compatibility, select components that have the same thread direction and size. 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 with Flange Ball Nut—Right-Hand Threaded

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

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.

		Ball Screw			Flange Ball Nut, mm
	Thread Size	Lg., mm	Root Dia., mm	Tensile Strength, psi	Lg.	Dia.	Lg. Tolerance Type	No. of Thread Starts	Travel Distance per Turn, mm	Accuracy for Travel Distance per Turn	Hardness	Dynamic Thrust Load Cap., lb.	Max. Backlash, mm	Temp. Range, ° F		Each
Carbon Steel Ball Screw with Alloy Steel Flange Ball Nut



		M8	150	6.6	21,000	28	20	Plus	1	2	±0.210 mm/300 mm	Rockwell C58	470	0.05	5 to 175	0000000	0000000


		M8	250	6.6	21,000	28	20	Plus	1	2	±0.210 mm/300 mm	Rockwell C58	470	0.05	5 to 175	000000	000000

Platform Ball Nuts—Right-Hand Threaded

Image of Product. Front orientation. Contains Annotated. Ball Screws and Nuts. Ball Screws and Nuts , Platform Nut, Ball 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.

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



	M25	35	60	45	20	1	5	Rockwell C58	1,500	0.1	5 to 175	0000000	0000000


	M25	94	60	55	23	1	10	Rockwell C58	7,000	0.1	5 to 175	0000000	000000

Metric Clamping Lead Screw Collars

Thread these one-piece collars onto a metric lead screw to separate and position components, or use them as an end stop to limit travel. Made of black-oxide steel, they have mild corrosion resistance. Tighten the clamping screws to secure.

To ensure compatibility, please select a collar that has the same thread type, direction, size, pitch, and number of thread starts as your lead screw.

	No. of Thread Starts	Hardness		Each
Right-Hand Thread







	Black-Oxide 1215 Carbon Steel

	M8 × 1.5 mm	18	9	1	Brinell 167	00000000	000000