Constant force coil springs for a DH Window

Hello, Dave. Without photos I can't say for sure what you have. It sounds like you already picked out the springs you need, though, which are our Series 195 and Series 196. If you can't read the stamps on the old springs then you will have to weigh your sash on a scale and divide that by how many springs support it. Then you can pick accordingly.

No, that's not how coil balances are identified. Every manufacturer uses their own type of balance, and even the same manufacturer can use a bunch of different balances from window to window. Then you have to account for the installers themselves, who may make last minute changes to get things to work. You'd be amazed what kind of wild stuff you'll see when someone's got a deadline. The kind of chart you're suggesting simply wouldn't be practical. Window size and even window brand won't tell you anything about the coil balance used.

I can ID your balance, but I'll need photos of the originals for reference. I especially need a photo of the pivot shoe, which is the most important detail, in addition to the thickness of the spring itself. We use physical details to ID parts. It's a lot easier and more reliable.

Thank you. Were you able to get a picture of the pivot shoe, as well? Like I said previously, it's the most important detail. Let me know if you can get that to me.

Thanks, let me know whenever you can get that.

Thanks, Dave, that's a huge help. That's our 15-111 shoe, which is compatible with two springs: the 3/8" thick Series 165 and the 1/2" thick Series 160. I think these parts are what you want, depending on the thickness of the shoe. Looks to be 1/2" to me, but I'm just eyeballing it.

If your spring is 1/2" thick then you want the Series 160, but there is no long or short version of this spring. I'm not really sure what you mean by that. They should both be the same size.

Since you have two springs per side and your sash weighs 23 pounds then you could probably get away with four 5.5 pound springs. That gives you 22 pounds of support. You could also do one 5.5 and one 6.5 spring on each side, which gives you 24 pounds. It's up to you.

That must just be an older style. We don't have springs designed this way but I don't think it will matter. In your case it seems both springs attach to the shoe, but in our case the top spring just attaches to the bottom spring. I can't see that making a big difference.

For a 23 pound sash, I recommend an S160-4 and S160-7 as well as the 15-111 shoe.