need replacements for spring balance 1930? windows

Question

We are restoring a meeting house we think was built in the 30"s and need ba in our spring balance replacements.  The length is 23" and the diameter is 3/8"

Tom · Accepted Answer

Thanks for reaching out to us. This is a very old non-tilt window spiral balance. These haven't been made in decades, but we have a few modern parts that can work.

Before I recommend anything, though, can you confirm what you're measuring for the diameter? You only want to measure the diameter of the outer tube, but I note that your outer tube is entirely missing. If you're just measuring the exposed spring itself then that's no good. Just something to keep in mind.

Assuming that the exposed spring itself is 3/8", then we can logically deduce that the outer tube was 9/16", which is the next (and only) size up. So I would recommend the Series 500 along with a new 17-012 bottom bracket.