38mm Springs | McMaster-Carr

As you stretch an extension spring, it gets harder to pull. Minimum load is the amount of force required to start to extend the spring. Maximum load is the amount of force required to fully extend the spring. Spring rate is the amount of force required for every inch or millimeter of extension.

For technical drawings and 3-D models, click on a part number.

Metric

			Load, lbs.
OD, mm	Wire Dia., mm	Extended Lg. @ Max. Load, mm	Min.	Max.	Spring Rate, lbs./mm	Material	Pkg. Qty.		Pkg.
38 mm Lg.
14	2	52.7	7.35	36.87	2.118	Music-Wire Steel	1	00000000	000000

Corrosion-Resistant Extension Springs with Hook Ends

Made of stainless steel, these springs are more corrosion resistant than steel springs. They're also easier to extend than steel springs. As you stretch an extension spring, it gets harder to pull. Minimum load is the amount of force required to start to extend the spring. Maximum load is the amount of force required to fully extend the spring. Spring rate is the amount of force required for every inch or millimeter of extension.

302 stainless steel springs have good corrosion resistance.

For technical drawings and 3-D models, click on a part number.

Metric

			Load, lbs.
OD, mm	Wire Dia., mm	Extended Lg. @ Max. Load, mm	Min.	Max.	Spring Rate, lbs./mm	Material	Pkg. Qty.		Pkg.
38 mm Lg.
14	2	52.7	7.35	30.71	1.76	302 Stainless Steel	1	00000000	000000

Extension Spring Stud Anchors

A black-oxide finish provides these steel anchors with mild corrosion resistance. Attach an extension spring to a stud and then thread the stud into your part for a secure connection.

For technical drawings and 3-D models, click on a part number.

Metric

Thread
Size	Pitch, mm	Min. Lg., mm	Lg., mm	Dia., mm	Hole Dia., mm	Material		Each
M8	1.25	25	38	8	5	Black-Oxide Steel	0000000	00000

Corrosion-Resistant Extension Spring Stud Anchors

These stainless steel anchor studs offer excellent corrosion resistance. Attach an extension spring to a stud and then thread the stud into your part for a secure connection.

For technical drawings and 3-D models, click on a part number.

Metric

Thread
Size	Pitch, mm	Min. Lg., mm	Lg., mm	Dia., mm	Hole Dia., mm	Material	Anchor Type		Each
M8	1.25	25	38	8	5	18-8 Stainless Steel	Stud	000000000	000000

Swiveling Extension Spring Stud Anchors

A black-oxide finish provides these steel anchors with mild corrosion resistance. The head swivels 360° so the spring stays straight and properly coiled. Attach an extension spring to a stud and then thread the stud into your part for a secure connection. To make tightening easier, anchors have a hex socket on the bottom and wrench flats at the top of the threads.

For technical drawings and 3-D models, click on a part number.

Metric

Thread
Size	Pitch, mm	Min. Lg., mm	Lg., mm	Dia., mm	Hole Dia., mm	Hex Size, mm	Material		Each
M8	1.25	25	38	8	5	2.5	Black-Oxide Steel	000000000	000000

Corrosion-Resistant Swiveling Extension Spring Stud Anchors

These stainless steel anchor studs offer excellent corrosion resistance. The head swivels 360° so the spring stays straight and properly coiled. Attach an extension spring to a stud and then thread the stud into your part for a secure connection. To make tightening easier, anchors have a hex socket on the bottom and wrench flats at the top of the threads.

For technical drawings and 3-D models, click on a part number.

Metric

Thread
Size	Pitch, mm	Min. Lg., mm	Lg., mm	Dia., mm	Hole Dia., mm	Hex Size, mm	Material		Each
M8	1.25	25	38	8	5	2.5	18-8 Stainless Steel	000000000	000000

Metric Color-Coded Die Springs

The colors and sizes of these springs follow ISO 10243 for metric die springs. Made of chrome-silicon steel, they have high tensile strength for reliable, long-lasting operation in repetitive applications, such as punching and stamping. All have closed and ground ends, which provide a flat mounting surface for even movement and distribution of loads.

Deflection is the distance the spring compresses, expressed as a percentage of its length.

As you squeeze a die spring, it gets harder to push. Spring rate is the amount of force required for every millimeter of compression. The higher the spring rate, the harder it is to compress the spring.

For technical drawings and 3-D models, click on a part number.

	Wire
Lg., mm	Thick., mm	Wd., mm	Compressed Lg. @ Max. Load, mm	Deflection @ Max. Load	Max. Load, lbs.	Spring Rate, lbs./mm	Material	End Type		Each
Green (Light Load Rating)
For 10 mm Hole Dia. (For 5 mm Shaft Dia.)
38	0.99	1.78	24.7	35%	20	1.5	Chrome-Silicon Steel	Closed and Ground	00000000	00000
For 12.5 mm Hole Dia. (For 6 mm Shaft Dia.)
38	1.32	2.36	24.7	35%	40	3	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 16 mm Hole Dia. (For 8 mm Shaft Dia.)
38	1.75	2.77	24.7	35%	57	4.3	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 20 mm Hole Dia. (For 10 mm Shaft Dia.)
38	1.91	4.19	24.7	35%	99	7.4	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 25 mm Hole Dia. (For 12.5 mm Shaft Dia.)
38	2.54	5.46	24.7	35%	185	13.9	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 32 mm Hole Dia. (For 16 mm Shaft Dia.)
38	2.92	7.24	24.7	35%	281	21	Chrome-Silicon Steel	Closed and Ground	00000000	0000
Blue (Medium Load Rating)
For 10 mm Hole Dia. (For 5 mm Shaft Dia.)
38	1.17	1.85	26.6	30%	30	2.6	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 12.5 mm Hole Dia. (For 6 mm Shaft Dia.)
38	1.55	2.39	26.6	30%	54	4.8	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 16 mm Hole Dia. (For 8 mm Shaft Dia.)
38	2.06	3.12	26.6	30%	86	7.6	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 20 mm Hole Dia. (For 10 mm Shaft Dia.)
38	2.36	3.96	26.6	30%	143	12.5	Chrome-Silicon Steel	Closed and Ground	0000000	0000
For 25 mm Hole Dia. (For 12.5 mm Shaft Dia.)
38	2.92	5.54	26.6	30%	238	20	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 32 mm Hole Dia. (For 16 mm Shaft Dia.)
38	3.96	7.14	26.6	30%	474	41	Chrome-Silicon Steel	Closed and Ground	00000000	00000
Red (Heavy Load Rating)
For 10 mm Hole Dia. (For 5 mm Shaft Dia.)
38	1.37	1.83	28.5	25%	36	3.8	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 20 mm Hole Dia. (For 10 mm Shaft Dia.)
38	3.18	4.19	28.5	25%	275	29	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 25 mm Hole Dia. (For 12.5 mm Shaft Dia.)
38	4.01	5.61	28.5	25%	467	49	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 32 mm Hole Dia. (For 16 mm Shaft Dia.)
38	5.08	7.26	28.5	25%	828	87	Chrome-Silicon Steel	Closed and Ground	00000000	00000
Yellow (Extra Heavy Load Rating)
For 10 mm Hole Dia. (For 5 mm Shaft Dia.)
38	1.50	2.03	30.4	20%	40	5.3	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 12.5 mm Hole Dia. (For 6 mm Shaft Dia.)
38	2.13	2.46	30.4	20%	61	8	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 16 mm Hole Dia. (For 8 mm Shaft Dia.)
38	2.79	3.20	30.4	20%	123	16.2	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 20 mm Hole Dia. (For 10 mm Shaft Dia.)
38	4.09	4.06	30.4	20%	302	39	Chrome-Silicon Steel	Closed and Ground	00000000	0000
For 25 mm Hole Dia. (For 12.5 mm Shaft Dia.)
38	4.95	5.49	30.4	20%	591	77	Chrome-Silicon Steel	Closed and Ground	00000000	00000
For 32 mm Hole Dia. (For 16 mm Shaft Dia.)
38	6.20	7.32	30.4	20%	902	118	Chrome-Silicon Steel	Closed and Ground	00000000	00000