sliding window 18" sash balance 1720

Question

These are what came out of the sides of our bathroom window. The window was jammed and when forced open, they pretty much fell out on their own. The plastic pieces on all the ends are broken so I can't show you what they're supposed to look like.

After a lot of internet search, I've determined they're "sliding window sash balances".

1/2" channel width.

9/16" depth.

The length of the metal is 18"

The only marking is "1720" and "B.S.I"

I would your recommendation as to what parts I need to get my window working again.

Thanks!

Tim

Casey · Accepted Answer

Hello,

With this combination of attachments, you could have either an S380-18 or S385-18 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. You'll also need 1720 spring strength options for your replacement balances.

It sounds like you may also need a new top sash guide if the balances do not stay in place below the sash. If so, we'd need to see an undamaged guide removed from the window to compare to our inventory.

Thank you and let us know if you have any other questions or concerns.

Comparison of the S378, S380 and S385 balance shoes.