Coil Spring for window

A quick learner from Missoula, MT says:
April 3, 2021
Hi,

I'm looking to replace the coil springs in a window. It looks like it matches the s150, but I don't know the balance weight. A stamp on the coil says 840 (see photo if possible).

Thanks

Bob
Thumbnail of the uploaded file named 16174777623977200805611653685850.jpg
Profile picture of Emily
Emily from SWISCO responded:
April 6, 2021

Thanks for posting. The 840 stamp indicates that the coil supports 8 pounds and has 40" of travel. Could you confirm that your coil is 1/2" thick? If it is, you'll need the S150-8 coil. If you have any further questions please let us know!
8 lb Series 150 Coil Balance
8 lb Series 150 Coil Balance
S150-8
$6.72
How to Replace a Triple Coil Balance System
How to Replace a Triple Coil Balance System
VIDEO
WATCH >
Removing a Triple Coil Window Balance
Removing a Triple Coil Window Balance
GUIDE
READ >
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.