replacement channel balance

Question

The original balance is from a Kinko non tilting window. The sash is double pane 48 x 28 and weights approximately 40-45 pounds. The original balance is 1/2  and has the markings 24 - 9 and NM BSI on the side no other markings.  I need and equivalent replacement or a matched pair suitable for the window.

Tom · Accepted Answer

I'm afraid I cannot identify what you have based on this information. Can you show me a picture of the balance out of the window? I will need to be able to clearly see both ends and the stamp. Please also tell me the exact weight of the sash, if possible.