Balance spring assembly : SWISCO.com

Handy Person from Portland Oregon

Aug 2, 2025 12:59 pm

I am trying to locate this spring assembly for my double hung window. It is 26" long and has a double spring (Smaller spring is inside the larger spring). The stamp on the balancer housing is"25DS 36." The balancer attaches with an inch long screw at the top.

3 user uploaded images

4 Replies

Casey from SWISCO

Aug 7, 2025 8:58 am

Hello,

We'd be happy to look into this for you, but the balance shown in your photos is too damaged to identify. We'll need to see the clip at the end of the pulley cord that connects to the pivot shoe below the balance to narrow down your options. Thank you!

Handy Person from Portland Oregon

Aug 7, 2025 9:41 pm

I already found replacement shoes and purchased them from your website. I just need a replacement balancer. Here are some more pictures of the spring and pulleys

4 user uploaded images

Casey from SWISCO

Aug 8, 2025 8:08 am

Thanks for getting back to us. Take a look at the S770-26 balances. The 25DS36 stamp indicates the balances are calibrated to support a sash of 36 pounds. If that is the weight of your sash, you can use the S770-26 with 26G strength options to support a sash between 34-38 pounds.

Close up view of the Series 770 balance top.

Close up view of the Series 770 balance bottom.