S140-10 how to mount

Hello!

The S140 installs with a screw. See the image below where I've circled the hole where the screw would go. There aren't standard sized channels. Each manufacturer designs their window differently. 

I'm not sure if the S140 is what you have, though. To confirm you get the right hardware for the job, can you show us some pictures of your pivot shoe removed from the window?  

Thank you kindly! This appears to be an older version of our 15-180 pivot shoe which is designed to use the Series 190 coil springs. Compare our dimensions with your old hardware to confirm this matches up. If you need a new single coil clip, see our 15-186.

I'm afraid we don't have a 10 pound S190 coil spring and using a 9 pound spring on both sides of the window may not be strong enough. With that said, you can use two S190-540 5 pound coil springs on both sides of the window which will total 20 pounds of overall support. You'll also need the 15-181 double coil support now that you'll be using two coils. 

I know you originally had a single coil spring setup but that doesn't really matter. The tension of the spring is important, not the number of springs.