Made-to-Order Extension Springs
Whatever the size, we'll get the spring you need. Send us a description, drawing, or sample of the extension spring you require.
Zinc-plated springs have mild corrosion resistance.
Stainless steel springs have good corrosion resistance. They’re generally easier to extend than steel springs.
Passivated stainless steel springs are more corrosion resistant than unfinished stainless steel springs.
To Order: Please specify the following:
1) End type: loop, hook, double loop, side loop; if you don’t see your end type, please select 9533K999.
2) Material: music-wire steel, spring-tempered steel, stainless steel, or other material.
3) Finish: plain, zinc-plated, or passivated (for stainless steel only).
4) Dimensions: length, body length, OD, and wire diameter.
Extension Spring Stock
Keep these springs on hand so you can cut the right length whenever you need it. All have straight-cut ends, which allow you to bend the end coils into hook or loop ends.
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. Spring rate is the amount of force required for every inch of extension.
To determine the spring rate of a cut spring, first multiply the spring’s original length by the spring rate given, then divide the result by the cut length (in inches).
For technical drawings and 3-D models, click on a part number.
| Wire Dia. | Min. Load, lbs. | Spring Rate, lbs./in.  | Material | End Type | Each | |
36" Lg. | ||||||
|---|---|---|---|---|---|---|
1/8" OD | ||||||
| 0.012" | 0.08 | 0.007 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.014" | 0.15 | 0.02 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.016" | 0.26 | 0.03 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.018" | 0.41 | 0.06 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.023" | 0.98 | 0.24 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
0.188" OD | ||||||
| 0.016" | 0.11 | 0.009 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.018" | 0.18 | 0.02 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.023" | 0.49 | 0.06 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.028" | 1.01 | 0.17 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
1/4" OD | ||||||
| 0.018" | 0.09 | 0.006 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.023" | 0.27 | 0.02 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.028" | 0.61 | 0.06 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.035" | 1.46 | 0.21 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
0.313" OD | ||||||
| 0.023" | 0.16 | 0.01 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.028" | 0.38 | 0.03 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.035" | 0.96 | 0.1 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.047" | 2.88 | 0.5 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
3/8" OD | ||||||
| 0.028" | 0.25 | 0.02 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.035" | 0.65 | 0.05 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.047" | 2.14 | 0.26 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.063" | 5.9 | 1.31 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
0.438" OD | ||||||
| 0.035" | 0.46 | 0.03 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.047" | 1.58 | 0.16 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
1/2" OD | ||||||
| 0.047" | 1.19 | 0.1 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.054" | 2.11 | 0.21 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.063" | 3.65 | 0.47 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.072" | 6.49 | 0.97 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.08" | 9.28 | 1.78 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
0.563" OD | ||||||
| 0.063" | 2.9 | 0.31 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
5/8" OD | ||||||
| 0.047" | 0.7 | 0.05 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.063" | 2.32 | 0.22 | Spring-Tempered Steel | Straight Cut | 0000000 | 0000 |
| 0.08" | 6.45 | 0.81 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.092" | 10.58 | 1.72 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
3/4" OD | ||||||
| 0.047" | 0.43 | 0.03 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.105" | 13.12 | 1.89 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.12" | 20.88 | 4 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
7/8" OD | ||||||
| 0.105" | 9.82 | 0.39 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.135" | 24.79 | 4.42 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
1" OD | ||||||
| 0.092" | 4.15 | 0.36 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.12" | 12.83 | 1.47 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
1 1/8" OD | ||||||
| 0.105" | 5.85 | 0.47 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.135" | 15.59 | 1.83 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
1 1/4" OD | ||||||
| 0.12" | 7.81 | 0.69 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
| 0.148" | 18.26 | 2.14 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |
1 1/2" OD | ||||||
| 0.162" | 18.22 | 1.86 | Spring-Tempered Steel | Straight Cut | 0000000 | 00000 |