Expansion Clamps | McMaster-Carr

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17-4 PH Stainless Steel

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Export Control Classification Number (ECCN)

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87 Products

Inside Diameter Fixture Clamps


Top Actuation	Side Actuation

Secure a workpiece from the inside diameter, leaving the outside clear for machining. Machine these clamps to match the precise size and contours of your workpiece ID. Mount the clamp to your fixture with the included screws and place your workpiece over it. Turn the socket head cap screw to expand the clamp.

Top Actuation—Top-actuated clamps tighten from the top of the clamp, so workpieces need a through hole.

Side Actuation—Side-actuated clamps tighten from the side of the clamp, gripping parts without a through hole in the top.

						Thread		Drive
	For ID Range	Max. Clamp Expansion	Ht.	Flange OD	Max. Clamping Force, lbf	Size	Lg.	Size	Style	Mounting Fasteners Included	No. of Mounting Holes	Material	Screw Material		Each
Top Actuation



		0.16" to 0.29"	0.005"	27/64"	25/32"	250	2-56	1/2"	5/64"	Hex	Yes	3	Steel	Steel	1341N11	000000


		0.28" to 0.49"	0.01"	55/64"	1 11/64"	950	8-32	1"	9/64"	Hex	Yes	3	Steel	Steel	1341N12	00000
		0.48" to 0.56"	0.013"	63/64"	1 15/64"	1,900	1/4"-20	1 1/4"	3/16"	Hex	Yes	3	Steel	Steel	1341N13	00000
		0.53" to 0.79"	0.015"	63/64"	1 15/32"	2,500	5/16"-18	1 1/4"	1/4"	Hex	Yes	3	Steel	Steel	1341N14	00000
		0.71" to 1.06"	0.015"	1 1/8"	1 31/32"	4,500	3/8"-16	1 1/2"	5/16"	Hex	Yes	3	Steel	Steel	1341N15	00000
		0.9" to 1.39"	0.015"	1 1/4"	2 13/64"	5,900	1/2"-13	1 1/2"	3/8"	Hex	Yes	3	Steel	Steel	1341N16	00000
		1.15" to 1.65"	0.015"	1 9/16"	2 47/64"	10,000	5/8"-11	1 3/4"	1/2"	Hex	Yes	3	Steel	Steel	1341N17	000000
		1.15" to 2.03"	0.015"	1 9/16"	2 31/32"	10,000	5/8"-11	1 3/4"	1/2"	Hex	Yes	3	Steel	Steel	1341N18	000000
		1.15" to 3.06"	0.015"	1 51/64"	4 15/64"	10,000	5/8"-11	2"	1/2"	Hex	Yes	3	Steel	Steel	1341N19	000000
		1.15" to 4.06"	0.015"	1 51/64"	5 15/64"	10,000	5/8"-11	2"	1/2"	Hex	Yes	3	Steel	Steel	1341N22	000000
		1.15" to 6.89"	0.02"	1 51/64"	5 15/64"	10,000	5/8"-11	2"	1/2"	Hex	Yes	4	Steel	Steel	1341N23	000000


		1.15" to 9.85"	0.08"	1 51/64"	6"	6,000	5/8"-11	2"	1/2"	Hex	Yes	4	Aluminum	Steel	1341N24	000000
		4.1 mm to 7.4 mm	0.13 mm	10.7 mm	20 mm	250	M2 × 0.4 mm	12 mm	1.5 mm	Hex	Yes	3	Steel	Steel	1341N311	00000
		7.1 mm to 12.4 mm	0.25 mm	21.8 mm	29.72 mm	950	M4 × 0.7 mm	25 mm	3 mm	Hex	Yes	3	Steel	Steel	1341N312	00000
		12.2 mm to 14.2 mm	0.33 mm	24.9 mm	31.5 mm	1,900	M6 × 1 mm	30 mm	5 mm	Hex	Yes	3	Steel	Steel	1341N313	00000
		13.5 mm to 20 mm	0.38 mm	24.9 mm	37.5 mm	2,500	M8 × 1.25 mm	30 mm	6 mm	Hex	Yes	3	Steel	Steel	1341N314	00000
		18 mm to 27 mm	0.38 mm	28.6 mm	50 mm	4,500	M10 × 1.5 mm	35 mm	8 mm	Hex	Yes	3	Steel	Steel	1341N315	00000
		23 mm to 35.3 mm	0.38 mm	31.8 mm	56 mm	5,900	M12 × 1.75 mm	40 mm	10 mm	Hex	Yes	3	Steel	Steel	1341N316	00000
		29.3 mm to 42 mm	0.38 mm	39.6 mm	69.5 mm	10,000	M16 × 2 mm	45 mm	14 mm	Hex	Yes	3	Steel	Steel	1341N317	000000
		29.3 mm to 51.5 mm	0.38 mm	39.6 mm	75.5 mm	10,000	M16 × 2 mm	45 mm	14 mm	Hex	Yes	3	Steel	Steel	1341N318	000000
		29.3 mm to 77.7 mm	0.38 mm	45.5 mm	107.5 mm	10,000	M16 × 2 mm	50 mm	14 mm	Hex	Yes	3	Steel	Steel	1341N319	000000


		Side Actuation



				0.71" to 1.12"	0.012"	1 5/8"	1 31/32"	4,000	—	—	1/4"	Hex	Yes	6	Steel	Steel	1341N21	000000

Inside Diameter Fixture Clamps for Castings and Rough Parts

These clamps wedge against the workpiece ID to grip cast, unfinished, or uneven parts, leaving the outside clear for machining. Do not use these clamps on smooth or finished ID’s because they will leave a mark. The clamp’s screw tightens from the top of the clamp, so workpieces require a through hole. Thread the clamp into a tapped hole in your fixture and place your workpiece over it. Reach through the hole to turn the screw, expanding the clamp.

					Thread		Drive
For ID Range	Max. Clamp Expansion	Overall Ht.	Body Ht.	Max. Clamping Force, lbf	Size	Lg., mm	Size, mm	Style	Mounting Fasteners Included	Material	Screw Material		Each



	0.768" to 0.945"	0.178"	29/64"	23/64"	450	M4 × 0.7 mm	12	3	Hex	Yes	Steel	Steel	3071N11	000000


	0.925" to 1.142"	0.217"	43/64"	33/64"	1,120	M6 × 1 mm	18	5	Hex	Yes	Steel	Steel	3071N12	00000
	1.122" to 1.417"	0.295"	7/8"	43/64"	2,000	M8 × 1.25 mm	25	6	Hex	Yes	Steel	Steel	3071N13	00000

Machinable Dual-Clamping Fixture Clamps

Machine these fixture clamps to match the contours of your workpieces for a stronger grip. Place the clamp between the two workpieces in a fixture and tighten the screw to extend the sides of the clamp, creating a secure hold against both workpieces. Minimal contact with the workpiece leaves more of its surface accessible for machining. Each clamp comes with a locking plate to keep the clamp rigid while machining it to fit your application.

					Thread		Drive
Lg.	Wd.	Ht.	Max. Clamping Force, lbf	Max. Machinable Wd.	Size	Lg.	Size	Style	Material	Screw Material	Wedge Material		Each



	5/8"	1 1/8"	1/2"	500	0.18"	8-32	5/8"	9/64"	Hex	Aluminum	Steel	Steel	3122N11	000000


	15/16"	1 1/2"	3/4"	1,500	0.26"	1/4"-20	7/8"	3/16"	Hex	Aluminum	Steel	Steel	3122N12	00000
	1 1/4"	2"	1"	2,500	0.39"	5/16"-18	1 1/4"	1/4"	Hex	Aluminum	Steel	Steel	3122N13	00000
	1 7/8"	3"	1 1/2"	3,500	0.62"	1/2"-13	2"	3/8"	Hex	Aluminum	Steel	Steel	3122N14	000000
	2 1/2"	4"	2"	6,000	0.8"	5/8"-11	2 1/2"	1/2"	Hex	Aluminum	Steel	Steel	3122N15	000000

Dual-Clamping Fixture Clamps

Set one of these clamps between two workpieces in a fixture and tighten the screw to push the clamp's sides out for a secure hold. The minimal contact leaves more of the workpieces free for machining.

				Thread		Drive					Each		Package
Lg.	Wd.	Ht.	Max. Clamping Force, lbf	Size	Lg.	Size	Style	Material	Screw Material	Wedge Material		Each	Pkg. Qty.		Pkg.



	5/16"	1/4"	17/64"	200	2-56	3/8"	5/64"	Hex	Aluminum	Steel	Steel	8693A15	000000	6	8693A65	000000


	15/32"	3/8"	3/8"	300	4-40	1/2"	3/32"	Hex	Aluminum	Steel	Steel	8693A16	00000	6	8693A66	00000
	5/8"	1/2"	37/64"	500	8-32	5/8"	9/64"	Hex	Aluminum	Steel	Steel	8693A11	00000	8	8693A61	00000
	15/16"	3/4"	49/64"	1,500	1/4"-20	7/8"	3/16"	Hex	Aluminum	Steel	Steel	8693A12	00000	6	8693A62	00000
	1 1/4"	1"	1 1/64"	2,000	5/16"-18	1 1/4"	1/4"	Hex	Aluminum	Steel	Steel	8693A13	00000	4	8693A63	00000
	1 7/8"	1 1/2"	1 33/64"	3,500	1/2"-13	2"	3/8"	Hex	Aluminum	Steel	Steel	8693A14	00000	2	8693A64	000000
	2 1/2"	2"	2 1/32"	6,000	5/8"-11	2 1/2"	1/2"	Hex	Aluminum	Steel	Steel	8693A17	000000	2	8693A67	000000
	8.1 mm	6.4 mm	6.9 mm	195	M2 × 0.4 mm	10 mm	1.5 mm	Hex	Aluminum	Steel	Steel	8693A71	00000	6	8693A75	00000
	11.9 mm	9.5 mm	9.7 mm	300	M2.5 × 0.45 mm	12 mm	2 mm	Hex	Aluminum	Steel	Steel	8693A72	00000	6	8693A76	00000
	15.9 mm	12.7 mm	14.5 mm	500	M4 × 0.7 mm	16 mm	3 mm	Hex	Aluminum	Steel	Steel	8693A73	00000	8	8693A77	00000
	23.8 mm	19 mm	19 mm	1,500	M6 × 1 mm	25 mm	5 mm	Hex	Aluminum	Steel	Steel	8693A74	00000	6	8693A78	00000


	31.7 mm	25.4 mm	25.9 mm	2,500	M8 × 1.25 mm	30 mm	6 mm	Hex	Aluminum	Steel	Steel	8693A81	00000	4	8693A79	00000

Expanding-Diameter Quick-Release Pins

With a shaft that expands to fill the hole completely, these pins withstand severe vibration and resist pulling. They’re often used to align fixtures during machining as well as open and close molds. Even with repeated insertion and removal, the shaft won’t wear the inside of holes like a retaining ball can. Flip the handle 180° to expand; flip back to contract the shaft and release.

Corrosion-Resistant Stainless Steel

Image of Attribute. Front orientation. Contains Annotated. Quick-Release Pins. Expanding-Diameter Quick-Release Pins.

High-Strength 17-4 PH Stainless Steel—The strongest stainless steel pins we offer, these are the least likely to deform due to stress and vibration. They resist rust in wet and outdoor environments but won't hold up to the harsh chemicals and acids that 316 stainless steel can.

	Handle Color	Handle Material		Each
High-Strength 17-4 PH Stainless Steel







	1/4" Diameter

	1"	8,000	Not Rated	Black	Aluminum	97787A661	0000000


	2"	8,000	Not Rated	Black	Aluminum	97787A662	000000




			5/16" Diameter

			2"	12,500	Not Rated	Black	Aluminum	97787A672	000000




					3/8" Diameter

					1"	18,000	Not Rated	Black	Aluminum	97787A681	000000


					2"	18,000	Not Rated	Black	Aluminum	97787A682	000000
					3"	18,000	Not Rated	Black	Aluminum	97787A683	000000




							1/2" Diameter

							1"	32,000	Not Rated	Black	Aluminum	97787A691	000000


							2"	32,000	Not Rated	Black	Aluminum	97787A692	000000
							3"	32,000	Not Rated	Black	Aluminum	97787A693	000000

Expandable Cam Handles for Unthreaded Holes

Use these handles to keep holes aligned or lift several sheets of thin material. They have a plug that expands to grip the edges inside holes. They are not suitable for permanent installation—use only for temporary mounting.

Unthreaded-Plug Mount

Plastic Handle—Made of plastic, these handles resist oil, grease, and solvents.

			Handle, mm
	For Hole Dia., mm	For Max. Material Thk.	Lg.	Wd.	Ctr. Ht., mm	Clamped Ht., mm	Max. Clamping Force, lbf	Plug Material	Washer Material		Each
Black Plastic Handle



		12	5/32"	72	16	14	22	11	Rubber	Plastic	1359N11	000000


		14	5/32"	72	16	14	22	13	Rubber	Plastic	1359N12	00000
		16	1/4"	100	24	16	29	13	Rubber	Plastic	1359N13	00000
		18	1/4"	100	24	16	29	22	Rubber	Plastic	1359N14	00000
		20	1/4"	100	24	16	29	22	Rubber	Plastic	1359N15	00000

Trigger-Action Bar Clamps/Spreaders

Shown as Spreader

Image of Product. Front orientation. Contains Annotated. Bar Clamps. Trigger-Action Bar Clamps/Spreaders.

Reverse the arms to use these clamps as spreaders. Press the trigger to slide the clamping arm along the bar. Release the trigger and squeeze the pistol-grip handle to lock the clamp in place.

	Opening		Spreader Opening
	Max.	Min.	Max.	Min.	Reach Lg.	Body Material		Each
300 lb. Holding Capacity



		6"	0"	12 1/2"	7 1/2"	2 1/4"	Steel	51755A6	000000


		12"	0"	18 1/2"	7 1/2"	2 1/4"	Steel	51755A7	00000
		18"	0"	24 1/2"	7 1/2"	2 1/4"	Steel	51755A11	00000
		24"	0"	30 1/2"	7 1/2"	2 1/4"	Steel	51755A12	00000
		36"	0"	42 1/2"	7 1/2"	2 1/4"	Steel	51755A13	00000


		600 lb. Holding Capacity



				6"	0"	14 7/8"	9 1/4"	3 5/8"	Steel	51755A21	00000


				12"	0"	20 1/2"	9"	2 3/4"	Steel	51755A22	00000
				18"	0"	26 1/2"	9"	2 3/4"	Steel	51755A23	00000
				24"	0"	32 1/2"	9"	2 3/4"	Steel	51755A24	00000
				36"	0"	44 1/2"	9"	2 3/4"	Steel	51755A25	00000
				50"	0"	58 1/2"	9"	2 3/4"	Steel	51755A26	00000

Parallel-Jaw Bar Clamps/Spreaders


	Shown as Spreader

The large, flat jaws remain parallel when clamping to apply even pressure without denting or marring the workpiece. Reverse the arms to use these clamps as spreaders. Pull the handle to lock or release the clamping arm.

Opening		Spreader Opening
Max.	Min.	Max.	Min.	Reach Lg.	Holding Cap., lb.	Body Material	Arm Material	Screw Material		Each
12"	0"	15 5/16"	10 1/2"	3 3/4"	1,000	Steel	Plastic	Steel	5022A11	000000
18"	0"	21 1/2"	10 1/2"	3 3/4"	1,000	Steel	Plastic	Steel	5022A13	00000
24"	0"	28 3/4"	10 1/2"	3 3/4"	1,000	Steel	Plastic	Steel	5022A15	00000
40"	0"	44 1/2"	10 1/2"	3 3/4"	1,000	Steel	Plastic	Steel	5022A17	00000
50"	0"	52 1/2"	10 1/2"	3 3/4"	1,000	Steel	Plastic	Steel	5022A18	00000

Fast-Action Bar Clamps/Spreaders


Shown as Spreader

Each arm slides freely for quick, one-handed positioning. They lock when the screws are tightened onto a workpiece. Reverse the arms to use these clamps as spreaders.

Opening		Spreader Opening
Max.	Min.	Max.	Min.	Reach Lg.	Holding Cap., lb.	Body Material	Screw Material		Each
16"	0"	30"	13 1/2"	4 3/4"	1,450	Steel	Black-Oxide Steel	2479N11	0000000
39 1/2"	0"	49"	13 1/2"	4 3/4"	1,450	Steel	Black-Oxide Steel	2479N12	000000
60"	0"	68"	13 1/2"	4 3/4"	1,450	Steel	Black-Oxide Steel	2479N13	000000