Spring Tensioners | McMaster-Carr

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58 Products

Spring-Loaded Adjustable-Arm Roller Chain and Belt Tensioners


Vertical Mount	Horizontal Mount	Replacement Springs

Tensioners take up slack and allow you to adjust tension on your roller chain or belt. A built-in spring allows the adjustment arm to apply continuous tension. They are for use with idler sprockets or pulleys.

Tensioners												Replacement Springs
		Mounting Plate
Thread Size	Tension Force, lbf	Ht.	Wd.	Tension Arm Lg.	Deflection Angle	Overall Dp.	Material	Arm Rotation	Includes		Each		Each







			Vertical Mount

			3/8"-16	45	5"	3 1/2"	5"	-45° to 45°	2 7/8"	Steel	180°	Idler Shaft, Internal Spring	60225K191	0000000	60225K29	000000


			1/2"-13	45	5"	3 1/2"	4 7/16"	-45° to 45°	2 7/8"	Steel	180°	Idler Shaft, Internal Spring	60225K21	000000	60225K29	00000
			5/8"-11	45	5"	3 1/2"	4 7/16"	-45° to 45°	2 7/8"	Steel	180°	Idler Shaft, Internal Spring	60225K22	000000	60225K29	00000
			3/4"-10	45	5"	3 1/2"	4 7/16"	-45° to 45°	2 7/8"	Steel	180°	Idler Shaft, Internal Spring	60225K27	000000	60225K29	00000




					Horizontal Mount

					3/8"-16	45	3 1/8"	4"	5"	-45° to 45°	2 1/2"	Steel	180°	Idler Shaft, Internal Spring	60225K192	000000	60225K29	00000


					1/2"-13	45	3 3/8"	3 1/4"	5"	-45° to 45°	4 5/16"	Steel	180°	Idler Shaft, Internal Spring	60225K23	000000	60225K29	00000
					5/8"-11	45	3 3/8"	3 1/4"	5"	-45° to 45°	4 5/16"	Steel	180°	Idler Shaft, Internal Spring	60225K24	000000	60225K29	00000
					3/4"-10	45	3 3/8"	3 1/4"	5"	-45° to 45°	4 5/16"	Steel	180°	Idler Shaft, Internal Spring	60225K28	000000	60225K29	00000

Heavy Duty Spring-Loaded Adjustable-Arm Roller Chain and Belt Tensioners


Tensioner Shown with Idler Shaft (Sold Separately)

Maintain correct drive tension to ensure smooth operation for maximum power and a long service life. Designed for use on large belt and chain drives, tensioners are spring loaded to provide constant tension and automatic adjustments for pulsating loads. Adjust the arm to control tension in a 360° arc. Idler shaft (sold separately) is required.

			Mounting Plate
Tension Force, lbf	For Idler ID	Wd.	Lg.	Ht.	Tension Arm Lg.	Deflection Angle	Material	Arm Rotation	Includes		Each



	22	1"	3"	8 11/16"	3 1/8"	5"	-90° to 90°	Steel	360°	Internal Spring	1816K1	0000000


	44	1"	3"	8 11/16"	3 1/8"	5"	-45° to 45°	Steel	360°	Internal Spring	1816K2	000000

Idler Shafts

			Overall		Thread
	Dia.	Lg.	Lg.	Dia.	Size	Lg.	Edge Type	Fabrication	Hardness Rating	Hardness	Includes		Each
Shaft Collar End







				1215 Carbon Steel

				1"	1 1/2"	3 3/8"	1 1/2"	3/4"-16	7/8"	Chamfered	Hardened	Extra Hard	Rockwell C58	Grease Fitting	1816K3	000000


				1"	2 1/2"	4 3/8"	1 1/2"	3/4"-16	7/8"	Chamfered	Hardened	Extra Hard	Rockwell C58	Grease Fitting	1816K4	00000
				1"	3 1/2"	5 3/8"	1 1/2"	3/4"-16	7/8"	Chamfered	Hardened	Extra Hard	Rockwell C58	Grease Fitting	1816K5	00000

Channel-Guided Roller Chain Tensioners

Built-in springs put constant tension on roller chain to absorb and buffer shock, reduce vibration, and improve drive performance.

				Overall					Mounting Holes
	For Roller Chain Trade No.	Tension Force, lbf	Travel Ht.	Ht.	Wd.	Dp.	Material	Housing Material	Dia.	No. of	Mounting Fasteners Included	Max. Temp., ° F		Each
For Single-Strand ANSI Roller Chain







				Vertical Mount/Horizontal Mount

				35	15 to 40	1.05"	5 15/32"	2 5/16"	1"	Plastic	Aluminum	3/8"	1	No	180	6233K62	0000000


				35	15 to 40	1.05"	5 19/32"	2 5/16"	1"	Plastic	Aluminum	3/8"	1	No	180	6233K33	000000
				40	15 to 40	1.05"	5 15/32"	2 5/16"	1"	Plastic	Aluminum	3/8"	1	No	180	6233K63	000000
				40	15 to 40	1.05"	5 19/32"	2 5/16"	1"	Plastic	Aluminum	3/8"	1	No	180	6233K34	000000
				50	20 to 60	1.2"	6 13/32"	2 15/16"	1 3/16"	Plastic	Aluminum	7/16"	1	No	180	6233K35	000000
				50	20 to 60	1.2"	6 15/32"	2 15/16"	1 3/16"	Plastic	Aluminum	7/16"	1	No	180	6233K64	000000
				60	20 to 60	1.2"	6 13/32"	2 15/16"	1 3/16"	Plastic	Aluminum	7/16"	1	No	180	6233K36	000000
				60	20 to 60	1.2"	6 15/32"	2 15/16"	1 3/16"	Plastic	Aluminum	7/16"	1	No	180	6233K65	000000
				80	45 to 100	1.5"	7 1/2"	3 17/32"	1 3/8"	Plastic	Aluminum	1/2"	1	No	180	6233K37	000000
				80	45 to 100	1.5"	7 25/32"	3 17/32"	1 3/8"	Plastic	Aluminum	1/2"	1	No	180	6233K66	000000
				100	45 to 100	1.5"	7 1/2"	3 17/32"	1 3/8"	Plastic	Aluminum	1/2"	1	No	180	6233K38	000000


				100	45 to 100	1.5"	7 25/32"	3 17/32"	1 3/8"	Plastic	Aluminum	1/2"	1	No	180	6233K67	000000


				For Double Strand ANSI Chain







								Vertical Mount/Horizontal Mount

								40	15 to 40	1.05"	5 15/32"	2 5/16"	1"	Plastic	Aluminum	3/8"	1	No	180	6233K75	000000


								40	15 to 40	1.05"	5 19/32"	2 5/16"	1"	Plastic	Aluminum	3/8"	1	No	180	6233K43	000000
								60	20 to 60	1.2"	6 15/32"	2 15/16"	1 3/16"	Plastic	Aluminum	7/16"	1	No	180	6233K77	000000


								For Single-Strand ISO Roller Chain







												Vertical Mount/Horizontal Mount

												06B	5 to 30	1.05"	5 19/32"	2 5/16"	1"	Plastic	Aluminum	3/8"	1	No	180	6233K88	000000

Heavy Duty Spring-Loaded Roller Chain and Belt Tensioners


Tensioner Shown with Idler Shaft (Sold Separately)

Designed for large belt and chain drives, these tensioners maintain correct drive tension for smooth operation, maximum power, and a long service life. They're spring loaded, which keeps constant tension on a belt or chain and automatically adjusts for changes in loads. An idler shaft (sold separately) is required.

			Mounting Plate		Overall			Mounting Holes
Tension Force, lbf	For Idler ID	Travel Ht.	Ht.	Wd.	Ht.	Dp.	Material	No. of	Lg.	Mounting Fasteners Included		Each



	84	1 1/2"	3"	7"	6"	18 5/16"	3 3/16"	Cast Iron	4	1 7/8"	Yes	5847N11	0000000

Idler Shafts

			Overall		Thread
	Dia.	Lg.	Lg.	Dia.	Size	Lg.	Edge Type	Fabrication	Hardness Rating	Hardness	Includes		Each
Shaft Collar End







				1215 Carbon Steel

				1 1/2"	3 1/4"	5 11/16"	2 1/4"	1"-14	1 5/16"	Chamfered	Hardened	Extra Hard	Rockwell C58	Grease Fitting	2435K104	000000


				1 1/2"	5 1/4"	7 11/16"	2 1/4"	1"-14	1 5/16"	Chamfered	Hardened	Extra Hard	Rockwell C58	Grease Fitting	2435K105	00000

Spring Installation and Removal Tools

Steel jaws hook onto compression or die springs to facilitate installation and removal.

For Spring Type	Overall Lg.	Jaw Material		Pair
Compression, Die	12 1/4"	Steel	6241A77	000000

Ultra-Low-Profile Channel-Guided Roller Chain Tensioners

Able to fit in tight spots, these tensioners are less than 3" tall. Built-in springs put constant tension on roller chain to absorb and buffer shock, reduce vibration, and improve drive performance.

				Overall					Mounting Holes
	For Roller Chain Trade No.	Tension Force, lbf	Travel Ht.	Ht.	Wd.	Dp.	Material	Housing Material	Dia., mm	No. of	Mounting Fasteners Included	Max. Temp., ° F		Each
For Single-Strand ANSI Roller Chain







				Vertical Mount/Horizontal Mount

				35	2 to 4	0.6"	2 9/16"	2"	19/32"	Plastic	304 Stainless Steel	5	2	No	140	7332K9	0000000


				35	13 to 19	0.6"	2 9/16"	2"	19/32"	Plastic	304 Stainless Steel	5	2	No	140	7332K11	000000

Low-Profile Channel-Guided Roller Chain Tensioners

At less than 4" in height, these tensioners are good for use on low-clearance drives. Built-in springs put constant tension on roller chain to absorb and buffer shock, reduce vibration, and improve drive performance.

				Overall					Mounting Holes
	For Roller Chain Trade No.	Tension Force, lbf	Travel Ht.	Ht.	Wd.	Dp.	Material	Housing Material	Dia., mm	No. of	Mounting Fasteners Included	Max. Temp., ° F		Each
For Single-Strand ANSI Roller Chain







				Vertical Mount/Horizontal Mount

				25, 35	7 to 13	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K1	0000000


				25, 35	13 to 29	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K5	000000
				40	7 to 13	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K2	000000
				40	13 to 29	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K6	000000
				50	7 to 13	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K3	000000
				50	13 to 29	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K7	000000
				60	7 to 13	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K4	000000
				60	13 to 29	1.6"	3 25/32"	2 25/32"	1 1/4"	Plastic	Steel	6	2	No	140	7332K8	000000

Constant-Tension V-Belt Drive Pulleys

A built-in spring maintains tension on your belt.

For 4L, 5L, A, AX, B, BX Belts

						Keyway
No. of Grooves	OD	For Shaft Dia.	Pitch Dia.	Wd.	Overall Wd.	Wd.	Dp.	Material	Body Type	Includes		Each
1	3.25"	1/2"	1.91" to 3.15"	11/16"	2 3/8"	—	—	Cast Iron	Solid	One Set Screw	6568K11	000000
1	3.25"	5/8"	1.91" to 3.15"	11/16"	2 3/8"	3/16"	3/32"	Cast Iron	Solid	One Set Screw	6568K12	00000
1	3.25"	3/4"	1.91" to 3.15"	11/16"	2 3/8"	3/16"	3/32"	Cast Iron	Solid	One Set Screw	6568K13	00000
1	4"	1/2"	1.95" to 3.9"	11/16"	2 7/16"	—	—	Cast Iron	Solid	One Set Screw	6568K21	000000
1	4"	5/8"	1.95" to 3.9"	11/16"	2 7/16"	3/16"	3/32"	Cast Iron	Solid	One Set Screw	6568K22	000000
1	4"	3/4"	1.95" to 3.9"	11/16"	2 7/16"	3/16"	3/32"	Cast Iron	Solid	One Set Screw	6568K23	000000
1	5"	5/8"	2.37" to 4.84"	15/16"	3 5/8"	3/16"	3/32"	Cast Iron	Solid	One Set Screw	6568K32	000000
1	5"	3/4"	2.37" to 4.84"	15/16"	3 5/8"	3/16"	3/32"	Cast Iron	Solid	One Set Screw	6568K33	000000
1	5"	7/8"	2.37" to 4.84"	15/16"	3 5/8"	3/16"	3/32"	Cast Iron	Solid	One Set Screw	6568K34	000000
1	5"	1"	2.37" to 4.84"	15/16"	3 5/8"	1/4"	1/8"	Cast Iron	Solid	One Set Screw	6568K35	000000

Brake Spring Pliers

Use the tips of these pliers to stretch your brake spring. The handle ends remove and install a spring from an anchor post.

		Jaw
	Overall Lg.	Max. Cap.	Lg.	Texture	Material	With Wire Cutter		Each
Curved Jaw and Plain Grip



		12 7/8"	5 3/4"	3 3/4"	Smooth	Steel	No	4597N11	000000

Overhead Door Spring Winding Rods

Keep your overhead door balanced on both tracks for smooth, even opening and closing. These winding rods help you safely increase and decrease the tension on the springs that hold the door. Their ends are machined to fit snugly into the springs' tensioning holes, giving you good control and preventing these rods from slipping out as you tension. Use these rods in pairs. For better leverage and easier winding, choose longer rods.

		Step
Dia.	Lg.	Dia.	Lg.	Material		Pair
1/2"	18"	7/16"	1 1/4"	Steel	6166N11	000000
5/8"	24"	1/2"	1 1/4"	Steel	6166N12	00000
5/8"	36"	1/2"	1 1/4"	Steel	6166N13	00000