Extension Springs with Special Ends
For specialty applications and connections, these springs have unique end types.
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 of extension.
All zinc-plated steel springs have mild corrosion resistance.
302 stainless steel springs have good corrosion resistance.
For technical drawings and 3-D models, click on a part number.
Load, lbs. | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Style | Lg. | OD | Wire Dia. | Extended Lg. @ Max. Load | Min. | Max. | Spring Rate, lbs./in.  | Material | Pkg. Qty. | Pkg. | |
Double Loop | |||||||||||
| B | 2" | 0.25" | 0.032" | 3.231" | 0.9 | 4.04 | 2.553 | 302 Stainless Steel | 2 | 0000000 | 000000 |
| B | 2" | 0.375" | 0.047" | 2.951" | 1.89 | 7.5 | 5.901 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 2" | 0.375" | 0.047" | 2.951" | 2.22 | 9.42 | 7.57 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 2" | 0.375" | 0.048" | 2.97" | 2.09 | 9.42 | 7.57 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 3" | 0.25" | 0.032" | 4.986" | 0.9 | 4.01 | 1.566 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 3" | 0.375" | 0.047" | 4.695" | 1.88 | 7.67 | 3.418 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 3" | 0.375" | 0.048" | 4.73" | 2.09 | 9.42 | 4.25 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 3 1/2" | 0.75" | 0.092" | 8.49" | 7.19 | 31.18 | 15.34 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 3 1/2" | 0.75" | 0.093" | 4.962" | 7.44 | 27.35 | 13.618 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 4" | 0.375" | 0.047" | 6.425" | 1.88 | 7.72 | 2.406 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 4" | 0.375" | 0.047" | 6.425" | 2.22 | 9.42 | 2.97 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 4" | 0.375" | 0.048" | 6.47" | 2.09 | 9.42 | 2.97 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 4" | 0.625" | 0.072" | 6.627" | 5.1 | 21.1 | 6.09 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 4" | 0.75" | 0.093" | 5.78" | 7.43 | 27.27 | 11.144 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 4" | 0.75" | 0.093" | 5.78" | 8.75 | 31.18 | 12.6 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 5" | 0.25" | 0.032" | 8.603" | 0.9 | 4.08 | 0.883 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 5" | 0.375" | 0.047" | 8.914" | 1.88 | 9.15 | 1.856 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 5" | 0.75" | 0.093" | 7.543" | 7.43 | 28.22 | 8.173 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 6" | 0.25" | 0.032" | 10.315" | 0.9 | 4.03 | 0.725 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 6" | 0.25" | 0.032" | 10.47" | 0.93 | 4.55 | 0.81 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 6" | 0.375" | 0.048" | 11.47" | 2.09 | 9.42 | 1.34 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 6" | 0.5" | 0.063" | 9.592" | 3.26 | 13.59 | 2.875 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 6" | 0.75" | 0.093" | 8.962" | 7.44 | 26.55 | 6.453 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 6 1/4" | 0.75" | 0.08" | 8.25" | 4.5 | 11.1 | 3.3 | Music-Wire Steel | 1 | 0000000 | 00000 |
| B | 8" | 0.5" | 0.063" | 13.175" | 3.26 | 13.99 | 2.073 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 8" | 0.5" | 0.063" | 13.31" | 3.52 | 15.58 | 2.27 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 8" | 0.625" | 0.072" | 14.26" | 3.96 | 19 | 2.4 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 8" | 0.625" | 0.072" | 14.667" | 4.33 | 18.06 | 2.058 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 8" | 0.625" | 0.072" | 14.667" | 5.1 | 21.1 | 2.4 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 10" | 0.5" | 0.063" | 16.599" | 3.26 | 13.96 | 1.621 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 10" | 0.5" | 0.063" | 16.599" | 3.84 | 15.58 | 1.78 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 10" | 0.5" | 0.063" | 16.78" | 3.52 | 15.58 | 1.78 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 10" | 0.625" | 0.072" | 18.649" | 4.33 | 18.16 | 1.598 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 10" | 0.625" | 0.072" | 18.649" | 5.1 | 21.1 | 1.85 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 12" | 0.5" | 0.063" | 20.046" | 3.26 | 13.97 | 1.331 | 302 Stainless Steel | 2 | 0000000 | 00000 |
| B | 12" | 0.5" | 0.063" | 20.046" | 3.84 | 15.58 | 1.46 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 12" | 0.625" | 0.072" | 21.89" | 3.96 | 19 | 1.52 | Zinc-Plated Spring-Tempered Steel | 3 | 0000000 | 00000 |
| B | 12" | 0.625" | 0.072" | 22.526" | 5.1 | 21.1 | 1.52 | Music-Wire Steel | 2 | 00000000 | 00000 |
| B | 15 3/4" | 1.125" | 0.105" | 17.79" | 6.01 | 8.45 | 1.22 | Music-Wire Steel | 1 | 00000000 | 00000 |
| B | 15 7/8" | 0.375" | 0.054" | 16.89" | 3.65 | 4.95 | 1.3 | Music-Wire Steel | 1 | 00000000 | 00000 |
| B | 16" | 0.296" | 0.041" | 17" | 2 | 2.64 | 0.64 | Music-Wire Steel | 1 | 00000000 | 00000 |
| B | 16" | 0.344" | 0.047" | 18" | 1.99 | 3.67 | 0.84 | Music-Wire Steel | 1 | 00000000 | 00000 |
| B | 16" | 0.421" | 0.062" | 17" | 4.7 | 6.9 | 2.2 | Music-Wire Steel | 1 | 00000000 | 00000 |
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.
