30 in window block and tackle sash balance

Question

Hello, I have 8 non tilting windows that need replacement springs so 16 pieces. The metal frame is 1/2 inches wide and 30 inches long.
No photos are available with the springs installed/attached because they are all broken.
There is a stamp on the frame 2930 if that's helpful. See attached photos for more details and I have more photos available. Thanks

Casey · Accepted Answer

Hello,

Your clip at the top of the jamb resembles the 16-028. As for the balances, you have either our S351-30, with a 15-002 bottom attachment, or S390-30, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. You'll also need a 2930 spring strength option for your replacement balances. Thank you!

Dimensions for 16-028

Comparison of the S351 and S390 balance shoes.