replacement window coil springs id needed

A handy person from Burlingame CA says:
Hi I have a vinyl Viking double hung window that needs two balance coil springs for the upper sash. The window size is 30 X 41 with double glazed frosted glass. I removed the parts and on the coil I could see it is etched with a large 7 then a smaller 37w at the end of the spring. Could you please tell me what spring I need for replacement. I also included pictures of the window sliders and the hinge mechanism. If you could Identify what type of hinge replacement I might need and if you have them incase they break in the future. Thank you for your assistance.

Brian C
User submitted photos of a coil window balance.
Profile picture of Paul
Paul from SWISCO responded:
You have the older model of our Series 180 coil balance system. Check it out and let me know what you think.
A handy person from Burlingame says:
That looks like it. Only question is what weight do I get?

Profile picture of Paul
Paul from SWISCO responded:
Based on the stamp printed on your coil spring, I would recommend the S180-7.
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)