Window sash balance

Hi there!

Thanks for reaching out to us. We're happy to help with this. Can you measure the bottom shoe as shown below? We would also like to see an image of the inside of the balance’s metal channel, where the innerspring connects to the pulley mechanism; this connection is located in the middle of the channel. 

Additionally, can you weigh the window sash on a scale and tell us the precise weight? Your stamp is from an older rating system so the sash weight will help us determine the correct stamp option. 

Profile view of a winged balance attachment

Thank you! If the bottom shoe is 1" deep when measured as shown below, you'd want the S380-20 channel balance. However, the window sash is the glass panel that moves up and down. We'll need you to weigh that, not the balances themselves. 

Comparison of the S378, S380 and S385 balance shoes.

Based on your sash weight, you would need 1960 strength options for the S380-20 balances to support a sash between 22-26 pounds. Just let us know if you need anything else.