Coil spring

Thanks for writing in! I believe our Series 140 Quick-Tilt coil balance assembly would be a good fit to replace your existing coil balance. To confirm that this is the right replacement, carefully compare the dimensions shown below. The image below is just for reference to compare the dimensions.

Alternate image for S140-8

To determine the spring strength needed to support the weight of your sash, you'll need to take a look at the coils springs for any stamps/markings. If there are none, you'll need to obtain the exact weight of the sash. Then you'll divide the sash weight by the number of coils supporting the sash.