Balance weight

Contractor from Belleville, Illinois

Feb 18, 2026 4:55 pm

I believe this is a 351 series balance. Unfortunately I don't have access to the window currently to weigh it. Does the 15C translate to the 1530?

3 user uploaded images

4 Replies

Casey from SWISCO

Feb 19, 2026 4:15 pm

Hello,

It looks like you have either our S351-16, with a 15-002 bottom attachment, or S390-16, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need.

You're correct that a 15C stamp would correspond to 1530 spring strength options for your replacement balances. Thank you!

Comparison of the S351 and S390 balance shoes.

Contractor from Belleville, Illinois

Feb 19, 2026 4:37 pm

Thank you!

Casey from SWISCO

Feb 20, 2026 8:12 am

No problem! Please let us know if you have any future hardware questions.