Bob from SWISCO responded:
July 23, 2023
Thanks for posting. I agree this shoe resembles the 15-199. Is the coil spring 3/8" thick? Let me know if it's 1/2" instead. If it's 3/8", then yes, you need Series 165 springs. If the window weighs 19.8 pounds, use two pairs of the S165-5 5 pound springs. Use two of these springs both sides of the sash. This equals 10 pounds of support on either side, for a total of 20 pounds overall, which is close enough to the exact sash weight. Let me know if you have further questions. |