Need new spring balance

Question

The spring balances for a small 6 -8 lb bathroom were rusted out so that I couldn't get the stamp number off of it.
The length of the metal channel is 18". Can you help me identify the right part. I will need two of them.
Thank you.

Bob · Accepted Answer

Thanks for posting. It looks like this is either an S380-18 or S385-18 Channel Balance. The only difference between these two balances is the depth of the bottom nylon shoe, or the measurement from 'heel' to 'toe'. See the diagram below for reference. Measure the shoe on your old balance to see what matches best. Let me know if neither seems right.

Comparison of the S378, S380 and S385 balance shoes.

For the stamp option, if the window sash in fact weighs between 6 and 8 pounds, a stamp option of 1710 should work, as this designates a balance that can support a sash in the weight range of 5 through 8 pounds. But I strongly advise obtaining the exact weight of the sash to ensure it falls in that range. Otherwise it is not going to work. Let me know if you have further questions.