Correct Coil balance weight

Question

I ordered 4 - S180-5 for my Traco windows but I'm not sure they are the correct weight after comparing the new one with the old coil. I included a picture of the old coil with a stamp on it with a large number 5 and in smaller type, 37w. There is also a picture of the coil housings. The last picture is comparing the new coil I ordered from you on left with the old coil on right.
My question is, did I order the correct weight coils?
Thanks for your help,
S. Lee

User submitted photos of a window balance.

Paul · Accepted Answer

I agree, the S180-5 looks to be the best match based on your old stamp. A good way to confirm this is to get the weight of your sash and divide it among the number of springs used to support it. For example, if your sash weighs 20 pounds, and you use four springs altogether, you would want springs that can carry 5 pounds each.