Step-Down Shafts | McMaster-Carr

Filter by

End Type

Plain

Splined

Step Down

System of Measurement

Diameter

Length

Step Diameter

Shaft Diameter

Shaft Type

Material

Shaft Coupling Connection

For Motion

Mechanical Finish

Shaft Keyway Width

Overall Length

Shaft Length

DFARS Specialty Metals

Exempt

REACH

Compliant

RoHS

Compliant

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

Yes

Export Control Classification Number (ECCN)

Hardness Rating

Step Length

Thread Size

Keyway Width

Bore Depth

104 Products

Step-Down Rotary Shafts

A shoulder acts as a stop for gears, sprockets, and bearings as well as components with smaller bore sizes. No need to machine these rotary shafts or install a shaft collar. Turned, ground, and polished to tight tolerances, they reduce vibration, evenly distribute loads, and improve accuracy.

Step-Down on One End

Carbon Steel—Strong and easy to machine. These shafts work best in dry environments since moisture will cause steel to rust.

Corrosion-Resistant 303 Stainless Steel—Withstand moisture and mild cleaning solutions, such as acetone and ammonia. These shafts are easier to machine than other stainless steel shafts.

		Step				Material
	Lg.	Dia.	Lg.	Straightness Tolerance	Dia. Tolerance	Hardness	Hardness Rating		Each
Carbon Steel







				3/4" Diameter

				6"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T1	000000


				9"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T2	00000
				12"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T3	00000




						1" Diameter

						6"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T4	00000


						9"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T5	00000
						12"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T6	00000


						Corrosion-Resistant 303 Stainless Steel







										3/4" Diameter

										6"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 160	Medium	8641T21	00000


										9"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 160	Medium	8641T22	00000
										12"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 160	Medium	8641T23	00000




												1" Diameter

												6"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 160	Medium	8641T24	00000


												9"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 160	Medium	8641T25	00000
												12"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 160	Medium	8641T26	00000

Step-Down on Both Ends

Carbon Steel—Strong and easy to machine. These shafts work best in dry environments since moisture will cause steel to rust.

		Step				Material
	Lg.	Dia.	Lg.	Straightness Tolerance	Dia. Tolerance	Hardness	Hardness Rating		Each
Carbon Steel







				3/4" Diameter

				12"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T51	000000


				18"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T52	00000
				24"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T53	00000




						1" Diameter

						12"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T57	00000


						12"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T54	00000
						18"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T58	00000
						18"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T55	00000
						24"	1/2"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T59	00000
						24"	3/4"	3"	0.003"/1 ft.	-0.001" to 0"	Brinell 150	Medium	8641T56	00000

Step-Down Shaft Adapters


For Keyed Shafts	For Round Shafts

Reduce the diameter of your shaft while adding length. One side of the adapter is a two-piece coupling that clamps onto your existing shaft; a smaller shaft extends from the other side. Tighten the clamping screws for a firm, even grip that won’t damage shafts.

Black-Oxide Steel—Black-oxide steel adapters have a finish that adds a layer of rust resistance but should be used in primarily dry environments. Because they’re steel, they balance high strength and good machinability, making them ideal for general purpose use.

303 Stainless Steel—303 stainless steel adapters resist corrosion in damp environments. They are easier to machine than other types of stainless steel but more difficult to machine than steel.

	Shaft Lg.	Bore Dp.	OD	Max. Rotation Speed	Max. Torque		Each
Black-Oxide Steel







	For Keyed Shafts

	3/4"	1/2"	3 1/2"	1 1/4"	1 5/8"	1 3/4"	Not Rated	Not Rated	9783T11	000000


	7/8"	5/8"	3 5/8"	1 1/4"	1 7/8"	1 7/8"	Not Rated	Not Rated	9783T12	00000
	1"	3/4"	3 5/8"	1 1/4"	2"	2"	Not Rated	Not Rated	9783T13	00000
	1 1/8"	7/8"	3 7/8"	1 1/2"	2"	2 1/8"	Not Rated	Not Rated	9783T14	00000
	1 1/4"	1"	4 1/2"	2"	2"	2 1/4"	Not Rated	Not Rated	9783T15	00000
	1 3/8"	1 1/8"	5"	2"	2 1/4"	2 3/8"	Not Rated	Not Rated	9783T16	00000
	1 1/2"	1 1/4"	5 3/8"	2 3/8"	2 1/4"	2 1/2"	Not Rated	Not Rated	9783T17	00000




			For Round Shafts

			3/8"	1/4"	2 1/8"	13/16"	1 1/8"	1 1/16"	Not Rated	Not Rated	9783T19	00000


			1/2"	3/8"	2 5/8"	1 1/8"	1 1/4"	1 1/4"	Not Rated	Not Rated	9783T18	00000
			3/4"	1/2"	3 1/2"	1 1/4"	1 5/8"	1 3/4"	Not Rated	Not Rated	9783T1	00000
			7/8"	5/8"	3 5/8"	1 1/4"	1 7/8"	1 7/8"	Not Rated	Not Rated	9783T2	00000
			1"	3/4"	3 5/8"	1 1/4"	2"	2"	Not Rated	Not Rated	9783T3	00000
			1 1/8"	7/8"	3 7/8"	1 1/2"	2"	2 1/8"	Not Rated	Not Rated	9783T4	00000
			1 1/4"	1"	4 1/2"	2"	2"	2 1/4"	Not Rated	Not Rated	9783T5	00000
			1 3/8"	1 1/8"	5"	2"	2 1/4"	2 3/8"	Not Rated	Not Rated	9783T6	00000
			1 1/2"	1 1/4"	5 3/8"	2 3/8"	2 1/4"	2 1/2"	Not Rated	Not Rated	9783T7	00000


			303 Stainless Steel







							For Keyed Shafts

							3/4"	1/2"	3 1/2"	1 1/4"	1 5/8"	1 3/4"	Not Rated	Not Rated	9783T34	000000


							7/8"	5/8"	3 5/8"	1 1/4"	1 7/8"	1 7/8"	Not Rated	Not Rated	9783T35	000000
							1"	3/4"	3 5/8"	1 1/4"	2"	2"	Not Rated	Not Rated	9783T36	000000
							1 1/4"	1"	4 1/2"	2"	2"	2 1/4"	Not Rated	Not Rated	9783T37	000000




									For Round Shafts

									3/4"	1/2"	3 1/2"	1 1/4"	1 5/8"	1 3/4"	Not Rated	Not Rated	9783T31	00000


									7/8"	5/8"	3 5/8"	1 1/4"	1 7/8"	1 7/8"	Not Rated	Not Rated	9783T32	00000
									1"	3/4"	3 5/8"	1 1/4"	2"	2"	Not Rated	Not Rated	9783T33	000000

Step-Up Shaft Adapters


For Keyed Shafts	For Round Shafts

Increase the diameter of your shaft while also making it longer. One side of these adapters clamp onto your shaft; the other side becomes your new larger end so you don’t have to replace the entire shaft. Tighten the clamping screws for a firm, even grip that won’t damage shafts.

303 Stainless Steel—303 stainless steel adapters resist corrosion in damp environments. They are easier to machine than other types of stainless steel but more difficult to machine than steel.

	Shaft Lg.	Bore Dp.	OD	Max. Rotation Speed	Max. Torque		Each
Black-Oxide Steel







	For Keyed Shafts

	1/2"	3/4"	2 3/4"	1 1/4"	1 1/4"	1 1/4"	Not Rated	Not Rated	3256K21	0000000


	5/8"	7/8"	3 1/4"	1 1/2"	1 3/8"	1 1/2"	Not Rated	Not Rated	3256K22	000000
	3/4"	1"	4 1/4"	2 3/8"	1 5/8"	1 3/4"	Not Rated	Not Rated	3256K23	000000
	7/8"	1 1/8"	4 3/8"	2"	1 7/8"	1 7/8"	Not Rated	Not Rated	3256K24	000000
	1"	1 1/4"	4 3/4"	2 3/8"	2"	2"	Not Rated	Not Rated	3256K25	000000
	1 1/8"	1 3/8"	4 3/4"	2 3/8"	2"	2 1/8"	Not Rated	Not Rated	3256K26	000000
	1 1/4"	1 1/2"	5"	2 1/2"	2"	2 1/4"	Not Rated	Not Rated	3256K27	000000




			For Round Shafts

			1/4"	3/8"	1 7/8"	7/8"	13/16"	13/16"	Not Rated	Not Rated	3256K19	00000


			3/8"	1/2"	2 1/2"	1 1/8"	1 1/8"	1 1/16"	Not Rated	Not Rated	3256K18	00000
			1/2"	3/4"	2 3/4"	1 1/4"	1 1/4"	1 1/4"	Not Rated	Not Rated	3256K11	00000
			5/8"	7/8"	3 1/4"	1 1/2"	1 3/8"	1 1/2"	Not Rated	Not Rated	3256K12	00000
			3/4"	1"	4 1/4"	2"	1 5/8"	1 3/4"	Not Rated	Not Rated	3256K13	00000
			7/8"	1 1/8"	4 3/8"	2"	1 7/8"	1 7/8"	Not Rated	Not Rated	3256K14	00000
			1"	1 1/4"	4 3/4"	2 3/8"	2"	2"	Not Rated	Not Rated	3256K15	00000
			1 1/8"	1 3/8"	4 3/4"	2 3/8"	2"	2 1/8"	Not Rated	Not Rated	3256K16	00000
			1 1/4"	1 1/2"	5"	2 1/2"	2"	2 1/4"	Not Rated	Not Rated	3256K17	00000


			303 Stainless Steel







							For Keyed Shafts

							1/2"	3/4"	2 3/4"	1 1/4"	1 1/4"	1 1/4"	Not Rated	Not Rated	3256K44	000000


							5/8"	7/8"	3 1/4"	1 1/2"	1 3/8"	1 1/2"	Not Rated	Not Rated	3256K45	000000
							3/4"	1"	4 1/4"	2"	1 5/8"	1 3/4"	Not Rated	Not Rated	3256K46	000000
							1"	1 1/4"	4 3/4"	2 3/8"	2"	2"	Not Rated	Not Rated	3256K47	000000




									For Round Shafts

									1/2"	3/4"	2 3/4"	1 1/4"	1 1/4"	1 1/4"	Not Rated	Not Rated	3256K41	00000


									5/8"	7/8"	3 1/4"	1 1/2"	1 3/8"	1 1/2"	Not Rated	Not Rated	3256K42	00000
									3/4"	1"	4 1/4"	2"	1 5/8"	1 3/4"	Not Rated	Not Rated	3256K43	000000

Mounted Linear Bearings for Ball Splines

A flange with mounting holes makes it easy to attach a load to these bearings. Create a compact linear and rotary motion system for robots and other applications requiring complex, fast movements, by combining them with ball splines. These bearings move smoothly and precisely even at high speeds along ball splines while grooves on the ball spline transmit rotary power. Clip a retaining ring (not included) into the groove on these bearings to position them in your system.

Steel Bearings


		For 4 Splines

												Groove, mm
For Spline Dia., mm	For No. of Splines	Overall Lg., mm	Flange OD, mm	Bolt Circle Dia., mm	OD, mm	Dynamic Load Cap., lb.	Static Load Cap., lb.	Max. Dynamic Torque, in·lbf	Max. Static Torque, in·lbf	Max. Temp., ° F	With Retaining Ring Grooves	Wd.	Dia.	No. of Mounting Holes		Each



	6	4	25	30	22	14	270	510	13	21	176	Yes	1.25	13.7	4	61145K41	0000000


	8	4	25	32	24	16	325	645	18	32	176	Yes	1.25	15.6	4	61145K42	000000
	10	4	33	42	32	21	610	1,100	38	72	176	Yes	1.65	20.5	4	61145K43	000000
	13	4	36	43	33	24	600	1,050	185	346	176	Yes	1.3	22.7	4	61145K111	00000
	16	4	50	50	40	31	1,350	2,500	531	973	176	Yes	1.6	29.4	4	61145K112	000000
	18.2	4	60	51	40	32	1,750	2,500	734	1,177	176	Yes	3	31.3	4	61145K46	000000
	20	4	63	58	45	35	2,000	3,650	929	1,717	176	Yes	2	33	4	61145K113	000000
	23	4	70	60	47	37	2,750	3,600	1,433	2,115	176	Yes	3.5	36.1	4	61145K47	000000
	25	4	71	65	52	42	2,850	5,250	1,672	3,062	176	Yes	2.5	39.5	4	61145K114	000000
	28	4	80	70	54	45	4,150	5,200	2,557	3,646	176	Yes	4	43.9	4	61145K48	000000
	30	4	80	75	60	47	4,150	5,200	2,716	3,885	176	Yes	3	44	4	61145K115	000000


	37.4	4	100	90	72	60	6,900	8,400	5,637	7,806	176	Yes	5	58.6	4	61145K49	000000
	40	4	100	100	82	64	6,900	8,400	5,964	8,266	176	Yes	4	60	4	61145K116	000000

52100 Alloy Steel Splines


	Splined End × Step-Down End

4 Splines

Image of Attribute. Front orientation. ZoomedIn view. Contains Annotated. Mounted Linear Bearings for Ball Splines.

Splines are alloy steel for high strength and wear resistance. They're hardened only on the outside, so they stand up to repeated motion while keeping their center soft enough to absorb stress from shifting loads.

Step-Down End—Splines with a step-down end have a shoulder near the end to stop gears, sprockets, and bearings.

		Spline				Step, mm
	Dia., mm	Lg., mm	No. of	Lg., mm	Root Dia., mm	Dia.	Lg.		Each
Splined End × Step-Down End



		18.2	200	4	350	16.4	15	150	61145K86	0000000


		23	200	4	350	20.6	20	150	61145K87	000000
		28	300	4	450	24.8	25	150	61145K88	000000
		37.4	400	4	550	33.1	30	150	61145K89	000000

Threaded Shaft Adapters


For Keyed Shafts	For Round Shafts

Adapt your shaft to a threaded end without having to machine threads onto your shaft. These adapters have a threaded end that mounts into tapped holes or can be used for threaded accessories, such as mixer propellers or fan blades. To attach these adapters to your existing shaft, tighten the clamping screws for a firm, even grip that won’t damage shafts. Made of steel, these adapters balance high strength and good machinability, making them ideal for general purpose use. They have a black-oxide finish that resists rust but should be used in primarily dry environments.

		Thread
	For Shaft Dia.	Size	Lg.	Overall Lg.	Bore Dp.	OD	Max. Rotation Speed	Max. Torque		Each
Black-Oxide Steel







				For Keyed Shafts

				1/2"	1/2"-13	1"	2 3/4"	1 1/4"	1 1/4"	Not Rated	Not Rated	4244N11	0000000


				5/8"	5/8"-11	1 1/4"	3 1/4"	1 1/2"	1 1/2"	Not Rated	Not Rated	4244N12	000000
				3/4"	3/4"-10	1 1/2"	4 1/4"	1 5/8"	1 3/4"	Not Rated	Not Rated	4244N13	000000
				1"	1"-8	2"	4 3/4"	2"	2"	Not Rated	Not Rated	4244N14	000000




						For Round Shafts

						1/2"	1/2"-13	1"	2 3/4"	1 1/4"	1 1/4"	Not Rated	Not Rated	4244N15	000000


						5/8"	5/8"-11	1 1/4"	3 1/4"	1 1/2"	1 1/2"	Not Rated	Not Rated	4244N16	000000
						3/4"	3/4"-10	1 1/2"	4 1/4"	1 5/8"	1 3/4"	Not Rated	Not Rated	4244N17	000000
						1"	1"-8	2"	4 3/4"	2"	2"	Not Rated	Not Rated	4244N18	000000

Linear Bearings for Ball Splines

Combine these bearings with a ball spline to create a compact linear and rotary motion system for applications with fast, complex movements, such as robotics. These bearings move smoothly and precisely even at high speeds along ball splines while grooves on the ball spline transmit rotary power. Clip a retaining ring into the groove on these bearings to position them in your system. Use the keyway and included machine key for attaching your load.

Steel Bearings


	For 4 Splines

										Groove, mm			Keyway, mm
For Spline Dia., mm	For No. of Splines	Overall Lg., mm	OD, mm	Dynamic Load Cap., lb.	Static Load Cap., lb.	Max. Dynamic Torque, in·lbf	Max. Static Torque, in·lbf	Max. Temp., ° F	With Retaining Ring Grooves	Wd.	Dia.	Includes	Lg.	Wd.	Dp.		Each



	6	4	25	14	270	510	13	21	176	Yes	1.3	13.3	Machine Key	10.5	2.5	1.2	61145K31	000000


	8	4	25	16	325	645	18	32	176	Yes	1.3	15.3	Machine Key	10.5	2.5	1.2	61145K32	00000
	10	4	33	21	610	1,100	38	72	176	Yes	1.7	20	Machine Key	13	3	1.5	61145K33	00000
	13	4	36	24	600	1,050	185	346	176	Yes	1.3	22.7	Machine Key	15	3	1.5	61145K12	00000
	16	4	50	31	1,350	2,500	531	973	176	Yes	1.6	29.4	Machine Key	17.5	3.5	2	61145K13	00000
	18.2	4	60	32	1,750	2,500	734	1,177	176	Yes	3.1	30.2	Machine Key	26	4	2.5	61145K36	000000
	25	4	71	42	2,850	5,250	1,672	3,062	176	Yes	2.5	39.5	Machine Key	36	4	2.5	61145K15	000000
	28	4	80	45	4,150	5,200	2,557	3,646	176	Yes	4.15	42.6	Machine Key	41	7	4	61145K38	000000
	30	4	80	47	4,150	5,200	2,716	3,885	176	Yes	3	44	Machine Key	42	4	2.5	61145K16	000000
	40	4	100	64	6,900	8,400	5,964	8,266	176	Yes	4	60	Machine Key	52	6	3.5	61145K17	000000

Stainless Steel Bearings


	For 4 Splines

Stainless steel bearings are more corrosion resistant than steel bearings.

										Groove, mm			Keyway, mm
For Spline Dia., mm	For No. of Splines	Overall Lg., mm	OD, mm	Dynamic Load Cap., lb.	Static Load Cap., lb.	Max. Dynamic Torque, in·lbf	Max. Static Torque, in·lbf	Max. Temp., ° F	With Retaining Ring Grooves	Wd.	Dia.	Includes	Lg.	Wd.	Dp.		Each



	6	4	25	14	270	510	13	21	176	Yes	0.6	13.4	Machine Key	10.5	2.5	1.2	61145K23	0000000


	13	4	36	24	600	1,050	185	346	176	Yes	1.3	22.7	Machine Key	15	3	1.5	61145K26	000000