Window spring balance

Thanks for reaching out to us. Can you confirm the diameter of the outer tube? I've never known any balance to be as skinny as 3/16". The only two available sizes are our Series 400 at 3/8" and our Series 500 at 9/16". Make sure to only measure the diameter of the outer tube.

As for sash weight, you can usually use the color of the original nylon tip as a reference for what to pick. Yours is pretty discolored, though, so I'm not sure what it used to be. You will have to do your best to get an accurate sash weight, even if it means putting a scale on the window sill itself. It's not ideal but there's no other way to confirm that.

Perfect, thanks so much, Jim. In that case it would be our S400-30 spiral balance. As for weight, both the Red Tip option (10 through 22 pounds) and Green Tip option (14 through 26 pounds) can carry your sash weight, so either one will work fine. I would personally go with Red but it's up to you.

You may also want to consider a 75-005 charging tool, which will make installation a lot easier.