Reasons Why Your Extension Spring Instant Quote Is Missing

No need to wait hours or days to get an extension spring quote. Our ISQ (Instant Spring Quote) gets the job done immediately. ISQ is a highly reliable fast quoting system for custom springs. It allows you to instantly view a list of extension spring prices and high discount rates based on different quantities. Furthermore, we continue to strive for excellence and are currently developing a new and improved version of our ISQ that will have enhanced features such as a 3d visual of your custom spring and a faster checkout process. Now, as great and practical as our Instant Spring Quote is, you may still encounter some special cases in which the specific coil spring you are trying to quote is not instantly quoted. This can be due to different reasons but below we will discuss some of the most common ones.

1. Wire Size:

When it comes to wire size, there are certain industry standards for wire size. If you input a wire size that does not exist we will be unable to quote your spring. You can adjust it to the closest available standard size of wire according to this standard wire size chart here.

Also, keep in mind that a wire size that is available in one material type may not be available in another. The following are the available wire sizes based on material type: 0.008" to 0.078" in both Music Wire ASTM A228(MW) and Stainless Steel 302 AST(SST 302. For sizes 0.079" to 1.250" please refer to the standard wire size chart previously mentioned.

NOTE: For extension springs, our ISQ will automatically quote springs with machine hooks, cross-over hooks, and no hooks. However, you will not get a quote if the length of the spring, including hooks, is not in the range of 0.200 in- 72 inches or if the spring has hooks and the wire size is over 0.050 inches. If this is your case, contact us and speak to one of our sales representatives to see if your design is achievable and get a quote.

extension spring wire

2. Material Type:

Material type is important and sometimes overlooked. There are certain material types that are not commonly available in certain wire sizes, but there are also extravagant materials that require us to quote your springs manually and on a case by case basis. Many times you can alternate for a similar material type but not always. When it comes to springs that will be placed under humid and corrosive environments you need to make sure that you stick to stainless steel material, or get a recommendation from one of our spring design engineers by emailing them at

extension spring material type

3. Index Issues:

Spring index refers to the correlation between the mean diameter and the wire diameter of a spring. The spring index assists in determining the manufacturability of the spring. It also signals as to how tight or lose the spring coils are which are factors involved in the force, stress, and elastic capacity of the extension spring. If your spring index is too small you will need to decrease the wire diameter or increase the outer diameter in order to increase it. On the other hand, If your spring index is too large, you will need to increase the wire diameter or decrease the wire diameter.

NOTE: The minimum index is 4.0 on wire diameters from 0.008" to 0.115" and 3.0 on wire diameters 0.118" and above and the maximum index is 25.0 on all wire diameters.

Index = Mean Dia. ÷ Wire Dia.

Mean Dia. = Outer Dia. – Wire Dia.

Mean Dia. = Inner Dia. + Wire Dia.

extension spring index range

We hope the previous information was helpful. If for some reason you are still not getting a quote for your extension spring, be sure to take a look at other possible reasons here: Instant Quote Help Page or contact us with a quote request at (951) 276-2777

We look forward to quoting your ideal extension spring!