balance block and tackle

Question

Help. I have 7 windows in my house that the balance block and tackles have broken. I need to replace them, but I am not sure the proper replacement part. The only stamp is 3940 on the bottom rail. The parts are 40" metal to metal, and 5/8" wide. I have attached pictures of the ends. Thanks.

Lee

User submitted photos of a window balance.

Casey · Accepted Answer

Greetings Lee. See if our S395-40 channel balance with a 3940 option would make a good replacement for you.