Double hung coil window balances

Question

I have two 17 1/4 x 71 3/8 double hung windows where many of the coil balances have broken. Each window has two single coils for one sash and two double coils for the second sash.

For the single coils, there is a stamp that appears to have "5K" on them. For the double coils, one spring has a "4K" and the other a "5K" (see picture).

The coils appear to be 1/2" wide with a diameter of 1 1/4". For replacing the coils I'm looking at is the "Series 152" (because of the size and the shape of the end of the spring (but that's just a guess).

With what I'm reading I need 8 coils to replace the "5K" coils and 4 coils to replace the "4K" ones.

Can you tell me the correct strength for the "4K" and "5K" coils from my photos?

I have other windows that will need repair in the future, but I'm starting with these two.

Thank you in advance for any help you can give.

Adam

Bob · Accepted Answer

Hi Adam. I agree, I believe these our Series 152 Coil Balances. The other tell is the pivot shoe--I believe it's either the 15-177 or 15-175, and both use the Series 152 springs. Remember that the identity of the pivot shoe almost always tells us the identity of the coil springs needed. Now, for springs stamped 5, use S152-5 5 pound springs as replacements. For springs stamped 4, use S152-4 4 pound springs. Let me know if you have any other questions.