coiled balance spring weight

Question

I have older Kohlertec windows approx 20 years old. They are double hung windows. I need the correct colide ba,ance springs. Your part # number looks what I need #S152. I have no idea od the weight. The only marking on the old spring is D

Casey · Accepted Answer

Hello,

Your pivot shoe looks like an older version of the 15-177. It works with Series 152 Coil Balance springs, sold separately. If the original springs have no numbers stamped on them, I'd suggest weighing your sash divided by the number of coils used on both sides to determine the correct strength options. For new coil covers, see the newer style 15-143, 15-144, and 15-145. These pieces 'sandwich' around each coil. Thanks for posting!

Alternate image for 15-177