Calibration spring

A handy person from Minneapolis says:
This broken spring on the window I am trying repair does not have a calibration number. How do I select the correct one?
Thumbnail of the uploaded file named IMG_6560.jpg
Profile picture of Lauren
Lauren from SWISCO responded:

Hello, thank you for posting,

Your pivot shoe resembles the 15-199 that is compatible with the 1/2" thick Series 160 coil springs or the 3/8" thick Series 165 coils. Please review the dimensions to confirm a good fit! 

To determine the weighted coil option needed, please provide which Series you have and the weight of the window sash to move forward. The sash will need to be removed and placed on a bathroom scale. Thank you! 

How to Replace a Triple Coil Balance System
How to Replace a Triple Coil Balance System
VIDEO
WATCH >
How to remove window pivot shoes
How to remove window pivot shoes
VIDEO
WATCH >
Anatomy of a tilt window
Anatomy of a tilt window
VIDEO
WATCH >
Removing Rusted Pivot Bars
Removing Rusted Pivot Bars
VIDEO
WATCH >
How to replace a window coil balance
How to replace a window coil balance
VIDEO
WATCH >
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)
Current wait time is 3-4 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at (888) 991-1929 or at help@swisco.com.