Spiral non tilt balance

Hello,

Based on your description, I would recommend starting by comparing the 3/8" diameter S400-28 spiral balance for non-tilt windows to your assembly. 

How to measure the length of the Series 400 spiral balance

Based on your sash weight, you could use either the red or green tip option. Both will support an 18-pound sash as shown below. If you notice any discrepancies, feel free to get back to us with photos of your original balance and we can go from there. Thank you.

Red: 10 to 22 lbs

Green: 14 to 26 lbs