Balance spring

Question

We are trying to find correct window balance spring.  The length of the metal is 37"  The metal has 3635 stamped on the flat part.   It has 2 plastic guides one on each end.  These are from Norandex windows.  Thanks

Lauren · Accepted Answer

Hello, thank you for posting,

With this combination of attachments, you could have either an S380 or S385 channel balance. You’ll need to measure as shown below. The Series 380 has a 1" bottom attachment, and the Series 385 has a 1-3/32" attachment.

The 3635 stamp does not directly translate to our stamp options. To further review, are you able to provide the weight of the window sash? The sash would need to be removed and placed on a bathroom scale. Thank you!

Comparison of the S378, S380 and S385 balance shoes.