3 1/2" Springs | McMaster-Carr

The farther you stretch these springs, the harder they pull to bring the two ends back together. They're commonly used to tension cable, return an air cylinder to its starting point, or hold a door closed.

Double-Loop End—Ends are strengthened by an extra loop, so these springs are less likely to break if overstretched.

Elongated-Hook End—With deeper hooks than standard hook end springs, these are less likely to slip off. However, they’re more prone to breaking if overstretched.

Spring Steel—Strong and resilient, but best suited for dry environments since moisture will cause these springs to rust.

Corrosion-Resistant 302 Stainless Steel—Won’t corrode from exposure to moisture and mild chemicals, including ammonia often found in cleaning solutions. These springs are easier to extend than steel, but can’t handle as high a load.

Minimum Load—The amount of force required to start extending the spring.

Maximum Load—The amount of force required to fully extend the spring.

					Load, lb.
	Lg.	OD	Wire Dia.	Extended Lg. @ Max. Load	Min.	Max.	Spring Rate, lbf/in	Pkg. Qty.		Pkg.
Double-Loop End







				Spring Steel

				3 1/2"	0.75"	0.092"	8.49"	7.19	31.18	15.34	3	1330K65	000000




						Corrosion-Resistant 302 Stainless Steel

						3 1/2"	0.75"	0.093"	4.962"	7.44	27.35	13.62	2	3795N33	00000


						Elongated-Hook End







										Spring Steel

										3 1/2"	0.25"	0.041"	4.04"	2.61	8.35	10.67	6	96605K21	00000

Spring Handles

Style 1

Also known as stove handles, these steel spring handles dissipate heat. Slide or weld them onto a shaft or rod to install.

Nickel Plated and Zinc Yellow-Chromate Plated—Nickel-plated and zinc yellow-chromate plated handles are mildly rust resistant.

	For Rod Dia.	Lg.	Max. Dia.	Mount Type		Each
Steel



	1	1/2"	3 1/2"	1 3/4"	Slide On, Weld On	4222N14	00000


	Nickel-Plated Steel



			1	1/2"	3 1/2"	1 3/4"	Slide On, Weld On	2449N11	0000


			Zinc-Yellow-Chromate-Plated Steel



					1	1/2"	3 1/2"	1 3/4"	Slide On, Weld On	4223N14	0000

Slotted Spring Pins


	End View

Squeeze these pins into holes and they expand slightly, creating tension to hold parts in place. They are often used as hinge pins and as fasteners for springs and power transmission components. An alternative to dowel pins, they're lighter in weight with a hollow center and don’t need a precise hole. Also known as roll pins.

Spring Steel—These pins won't deform from stress and vibration. Although they're stronger than stainless steel, they're best for dry environments since moisture will cause them to rust.

Zinc-Plated Spring Steel—These pins withstand occasional exposure to moisture. However, since friction from moving parts can wear away the finish, they're not ideal for wet environments. While not nearly as corrosion resistant as stainless steel, they are stronger and won’t deform under stress.

Corrosion-Resistant 18-8 Stainless Steel—The choice for wet and outdoor environments, these pins resist rusting. They are strong enough to join most components but won't withstand extreme stress and vibration as well as steel.

Wear-Resistant 400 Series Stainless Steel—Our most wear-resistant stainless steel pins, these are good for pivoting parts that create a lot of friction. They hold up in environments that experience occasional moisture, but they're not as corrosion resistant as 18-8 and 316 stainless steel.

	Double Shear Breaking Strength, lbf	Min. Hardness	Specs. Met	Pkg. Qty.		Pkg.
Spring Steel







	1/4" Diameter

	3 1/2"	0.25" to 0.256"	0.048"	7,000	Rockwell C43	ASME B18.8.2	50	98296A937	000000




			5/16" Diameter

			3 1/2"	0.312" to 0.318"	0.062"	10,800	Rockwell C43	ASME B18.8.2	25	98296A007	00000




					3/8" Diameter

					3 1/2"	0.375" to 0.382"	0.077"	16,300	Rockwell C43	ASME B18.8.2	10	98296A955	00000




							1/2" Diameter

							3 1/2"	0.5" to 0.51"	0.094"	27,000	Rockwell C43	ASME B18.8.2	10	98296A679	00000


							Zinc-Plated Spring Steel







											1/4" Diameter

											3 1/2"	0.25" to 0.256"	0.048"	7,000	Rockwell C43	ASME B18.8.2	25	90692A755	00000




													5/16" Diameter

													3 1/2"	0.312" to 0.318"	0.062"	10,800	Rockwell C43	ASME B18.8.2	10	90692A767	0000




															3/8" Diameter

															3 1/2"	0.375" to 0.382"	0.077"	16,300	Rockwell C43	ASME B18.8.2	10	90692A781	00000




																	1/2" Diameter

3 1/2"																	0.5" to 0.51"	0.094"	27,000	Rockwell C43	ASME B18.8.2	10	90692A676	00000


Corrosion-Resistant 18-8 Stainless Steel







																	1/4" Diameter

	3 1/2"																0.25" to 0.256"	0.048"	4,100	Not Rated	ASME B18.8.2	5	92373A389	00000




																	5/16" Diameter

			3 1/2"														0.312" to 0.318"	0.062"	6,300	Not Rated	ASME B18.8.2	1	92373A473	0000




																	3/8" Diameter

					3 1/2"												0.375" to 0.382"	0.077"	9,500	Not Rated	ASME B18.8.2	1	92373A568	0000




																	1/2" Diameter

							3 1/2"										0.5" to 0.51"	0.094"	15,800	Not Rated	ASME B18.8.2	1	92373A685	0000


							Wear-Resistant 400 Series Stainless Steel







																	1/4" Diameter

											3 1/2"						0.25" to 0.256"	0.048"	7,000	Rockwell C43	ASME B18.8.2	10	92383A769	00000




																	5/16" Diameter

													3 1/2"				0.312" to 0.318"	0.062"	10,800	Rockwell C43	ASME B18.8.2	5	92383A779	0000




																	3/8" Diameter

															3 1/2"		0.375" to 0.382"	0.077"	16,300	Rockwell C43	ASME B18.8.2	1	92383A791	0000




																	1/2" Diameter

3 1/2"																	0.5" to 0.51"	0.094"	27,000	Rockwell C43	ASME B18.8.2	1	92383A680	0000

Heavy Duty Coiled Spring Pins


	End View

Made of thicker material than our other coiled spring pins, these are about 30% stronger with the same resilience to vibration and shock. They are often used in power transmission, automation, and other assemblies with constant motion and sudden starts and stops. Because of their spiral shape, pins flex to conform to holes that aren’t perfectly round.

Spring Steel—These pins won't deform from stress and vibration. Although they're stronger than stainless steel, they're best for dry environments since moisture will cause them to rust.

	Min. Hardness	Specs. Met	Pkg. Qty.		Pkg.
Spring Steel







	5/8" Diameter

	3 1/2"	0.618" to 0.635"	Not Rated	Rockwell C42	ASME B18.8.2	1	95755A749	000000

Tooth-Slotted Spring Pins

End View

The interlocking teeth resist pulling forces that can cause other slotted pins to wiggle out of place. These pins stay in position under vibration and in holes that aren't perfectly round. Compress pins to insert them in a hole. Once installed, they expand slightly and create tension to hold parts in place. Also known as roll pins.

Black-Oxide Spring Steel—These pins won't deform from stress and vibration. The dark, matte coating creates a finished look with minimal corrosion resistance, so they're best for dry environments.

	Double Shear Breaking Strength, lbf	Min. Hardness		Each
Black-Oxide Spring Steel







	5/8" Diameter

	3 1/2"	0.625" to 0.626"	0.115"	13,800	Rockwell C42	90354A106	000000

Coiled Spring Pins


	End View

The best spring pins for joining parts exposed to vibration and shock. They're often used in power transmission, automation, and other assemblies with constant motion and sudden starts and stops. Because of their spiral shape, they flex to conform to holes that aren’t perfectly round.

Spring Steel—These pins won't deform from stress and vibration. Although they're stronger than stainless steel, they're best for dry environments since moisture will cause them to rust.

	Min. Hardness	Specs. Met	Pkg. Qty.		Pkg.
Spring Steel







	1/4" Diameter

	3 1/2"	0.247" to 0.256"	5,500	Rockwell C42	ASME B18.8.2	10	91598A502	000000




			3/8" Diameter

			3 1/2"	0.375" to 0.383"	12,600	Rockwell C42	ASME B18.8.2	5	91598A578	00000

Wood Screw-Style Hangers

Drive these hangers into wood with an adjustable wrench, pliers, or a special driver bit (sold separately). They’re also known as eye lags.

Zinc-Yellow-Chromate-Plated Steel—Zinc- and zinc yellow-chromate plated steel hangers are corrosion resistant in wet environments. The zinc yellow-chromate plated steel hangers meet quality standards outlined in ASTM B633 and dimensional standards outlined in ASME B18.2.1.

	Hanger Bolts														Driver Bits
						Head
	Screw Size	Lg.	Threading	Thread Lg.	Eye Dia.	Wd.	Thk.	Ht.	Max. Wt. Cap.	For Use In	Specs. Met	Pkg. Qty.		Pkg.		Each
Zinc-Yellow-Chromate-Plated Steel



		5/16"	3 1/2"	Partially Threaded	1 3/4"	1/4"	7/16"	3/32"	9/16"	Not Rated	Wood	ASME B18.2.1, ASTM B633	25	90171A597	000000	5977A43	000000