Broken balance spring replacement

Question

I'm trying to find and order replacement parts for my window. The balance spring broke

Emily · Accepted Answer

Hello!

It appears your balance matches our S380-27 or S385-27 depending on the size of your bottom shoe. Our Series 380 has a 1" deep shoe, and the Series 385 has a 1-3/32" deep shoe so you'll need to measure as shown below to determine the best replacement option. I also recommend the 2640 strength option, based on your 26-4 stamp.

Comparison of the S378, S380 and S385 balance shoes.