Spiral window balance

Question

My house is 87 years old. Someone screwed the broken windows shut. Every one of these windows needs spiral replacement. They are 27 inch with a bracket screwed to bottom of window. The bracket I found on the website but I don't know which spiral unit to purchase. Thanks for your help.

The tube length is 27 inches
The tube is 3/8 inches diameter
The spiral is permanently attached to window connector. It has no color and is permanently attached. See attached image.

I don't know the weight of the window or even how to measure it. I have 11 windows that need spirals replaced. These spirals are 87 years old.
Thank you for your time.

Casey · Accepted Answer

Hello,

Unforutnately, your old style spiral balances that rivet onto the sash bracket are no longer available. With that being said, we often recommend the 5/8" diameter S500-27 spiral balances for older wood windows like yours, which attach to the 17-012 sash bracket. We also carry the 3/8" diameter S400 balances, but we do not recommend them for wood windows since they are generally heavier than these balances are intended to support. Take a look and see if you'd have space to install the larger 5/8" balances.

There is a chart on the product page that explains how to choose your color option based on the sash weight. With the balances released on both sides, you can lower the sash onto a bathroom scale resting on the windowsill to determine the weight. Thanks for posting.

Guide: How to adjust a spiral balance on a non-tilt window