Balance spring

Question

Single hung window balance spring broken,
it reads: "25 5 AX CMC 1" on the side of it
please let me know which one to purchase. Thank you.

Bob · Accepted Answer

Thanks for posting. See our S380-26 or S385-26. The only difference between these two channel balances is the 'depth' of the bottom nylon shoe. See below. Measure your old balance's shoe depth to see what matches best. For a stamp option choose 2550.

Comparison of the S378, S380 and S385 balance shoes.