Coil balance and pivot pin identification

Question

I have a slightly different style of coil balance than your series 161, but the specifications seen to match (it's 9/16 thick and 1 1/4 wide).
I couldn't read the rating on it, but it appears to be a 6, although the window weighed 10.4 lbs when I checked it.
Is a pair of 6 lb series 161 coil balances the correct replacement?
Also, are they compatible with your stainless 26-313 pivot bars?
My bars seem to match the length and hole spacing, and my channel appears to be 5/16 x 3/16.
I'm in a coastal area, so the stainless would be great if it works (as evidenced by the extreme rust on the one currently installed).
Thanks in advance!

Bob · Accepted Answer

While this coil balance system resembles the Series 161, I believe you actually have the 15-087 Pivot Shoe, which uses Series 180 Coil Balances instead. If the window weighs exactly 10.4 pounds, you'll need two of the S180-5 5 pound springs, one for each side of the sash. That will total 10 pounds of support--being within 1 pound of the exact sash weight is fine. For the pivot bar, see if the 26-040 or 26-063 match what you need.

Detail of 15-086