Do you have a 9 pound Series 190?

Question

One single coil balance spring in my one double glazed window was broken. I took it off and checked the number stamped on it. It can be read as "9" or "6" but I weighed this window, which is about 20 lbs. However, I do not find any product in S190 series that can hold 9 lbs. If it is "9", it means the builder installed the 9-lb single coil balance sring on each side in the first place, which tries to hold a 20 lbs sash.

I don't want to make any change from single coil to double coils because it will drill hole on frame at different location, which will makes frame weaker.

Can I buy S190-840 to replace the broken one (just 1 lb shorter) or it is really number "6" because the manufacture has never made 9 lb coil balance spring?

Thanks,

Han

Tom · Accepted Answer

It's possible the installers used a 9 pound spring, but I'm afraid we don't have anything that strong. You may want to consider using two weaker springs to make up the difference, like using two S190-540 coils on each side. Two 5 pound springs on each side would be perfect for your sash weight. You'd also need a new clip, our 15-181, and an extra bushing on each side, our 15-182. See what you think.