Atrium Window from 2016, replacement balance spring

Question

Balance is 1-1/4" wide, 1/2" thick. Writing on the spring says 35", 7.5#, W2H. Part numbers are visible, I have shown those in pictures.

Bob · Accepted Answer

Thanks for posting. This looks like a Series 160 Coil Balance. If the stamp reads '7.5', use the S160-07 7.5 pound spring. I can't really make out your pivot shoe in these photos, but I suspect it's the 15-228. Please compare.

Dimensions for 15-228

For new coil housing, see either the 15-150S single support or 15-150D double support, depending how many coils there are on each side of the window. Let me know if you have further questions.