window balance spring I 3020

Question

Hi. It's a big double hung. Approx. 20 year old Marvin. I only need the inside Bottom) sash springs.
Engraved identification: l 3020
Metal spring housing is ~1 1/2 in (or a bit more) wide, 5/8th in deep, and 31 in long.
Sash itself is 50 3/8 in wide, 34 1/4 in height, and 2 3/16 in thick.

Thanks!

Tom · Accepted Answer

Hello! It's tough to tell what you have while it's still installed, but your balance looks very similar to our Series 751 channel balance. I recommend carefully examining the design of this balance to ensure that it matches your original. If you have any doubts, though, let me know and I will do my best to advise.

Close up view of the S751 balance top.

Close up view of the S751 balance shoe.

Close up view of the S751 balance top.

Close up view of the S751 balance shoe.