Coil Balance Spring replacement

Question

I'm replacing a coil balance spring in a nominal 36" X 36" vinyl, double-hung window. It is a dual-glazed, tempered, obscured glass bathroom window. I can't find a manufacturer's label anywhere.

I've determined it is a S160 spring (1/2" wide with a short "T" tongue).

There are no coil strength markings on the spring that I can see. Could you recommend a spring tension weight?

Emily · Accepted Answer

Thanks for reaching out to us. Since the old spring doesn't have any markings, you'll need to divide the sash weight by the total number of springs in the window to determine the appropriate spring weights.