Window Channel Balances

Question

The one I am showing is a 15" (measuring the metal part only)
1/2 " width when looking at the spring
The markings are: B 15 and 3.S.I.

The window doesn't tilt: straight push up or down
Going back to around 1983
The windows are Western Products

I have other, larger windows that will need replacement too. They are the same type, manufacturer, ... but larger.

Bob · Accepted Answer

If the metal channel, not including the nylon fittings, is 15" long, then this appears to be a S350-15. The stamp code '15B' is pretty unusual for a balance of this size though; for non-tilt window channel balances, typically those first two digits is one number less than the actual balance length. It's possible these balances were cut down to size to fit your window. Either way, to know what stamp option to select, you'll need to obtain the exact weight of your window sash. You can then match that exact weight with one of the weight ranges listed alongside each stamp option on the balance product page.