Window sash coil balances

Thanks for writing in. This looks like our 15-111 Pivot Shoe. This shoe uses either our Series 160 or Series 165 Coil Springs, depending on the thickness of your old coil springs. I'm afraid we can't tell the weight of your window sash that from that information alone. If you could get the exact weight on a bathroom scale, we can work out the coil balances you need. Many thanks.

Thanks for getting back to me. If your coil springs are 1/2" thick then you need our Series 160 springs. If your window sash weighs 23 lbs, then I would use (4) of our S160-5 springs, with a pair on each side of the window sash. These springs support 5.5 lbs of weight individually, so having a pair of these on each side of the sash would total 22 lbs of support. With Coil Balances, being within 1 lb of the exact window sash weight is fine. Let me know if you have any other questions.