Spring Length

Question

I recently ordered (order#1101706) a pair of "BSI 26 3" replacement balances. Thought I picked the right one, but as you can see in this crappy photo, the springs were a little longer than the original. Every other aspect was the same. I installed them and they seem OK. So what difference does the longer spring make? Lift more weight? Less weight? Which should I have ordered? Or is that the correct replacement?

Tom · Accepted Answer

Thanks for posting! The length of the spring doesn't matter. Some manufacturers make them long, some make them short. It's irrelevant, though. What matters is the tension of the spring, which cannot be identified by looking at it. A long spring and short spring can both have the same tension, you see.

Balance spring tension is separated into certain categories indicated by the stamp printed on the channel. Your old stamp was 26 3, which corresponds to our 2630 option. This carries 13 through 19 pounds. As long as your sash falls in this weight range, you should be okay.