21" channel balance stamped 20 9 #30 CALDWELL

Question

I have figured out I need a 21" series 385 balance but the spring weight only goes up to 27 lbs.

The stamp on the old balance indicates I need a spring for 30 lbs. What option should I do?

Bob · Accepted Answer

Thanks for posting. Yes, the stamp '20 9' comes from an older rating system for spring strength that we no longer use. I am not certain if the #30 necessarily represents the weight of the sash; it's possible, but I think it would be best to confirm this. Could you weigh your window sash? If it turns out that precise weight falls within one of the weight ranges for the stamp options listed on the S385-21 product page, then you should be good to go with one of the conventional options. If it does indeed weigh beyond the standard range, then just let us know and we can work out a special order for you. Thanks.