Channel Balance ID?

A home owner from Palm city,Fl says:
February 25, 2015
I have a 35" X 9/16" balance with 3440 stamped on it. Window has a 5/8" sash guide, Norandex 18-161.

Balance looks similar to your 35" Series 380. My top piece and shoe (see photos) look similar to yours.

Do I have the correct part? What is the 3440 option?
User submitted photos of a window balance.
Profile picture of Tom
Tom from SWISCO responded:
February 25, 2015
I agree, the Series 380 looks close. Just make sure the dimensions on your nylon attachments match ours.

The stamp option determines the spring strength. Since your current stamp reads 3440, I think it's safe to say that our 3440 option is what you want. If you still want to be sure, though, you can always weigh your sash and cross-reference the chart we show on the S380-35 store page.
A home owner from Palm City, Fl says:
February 26, 2015
Thanks for your reply.
Regarding the sash weight, my scale says 33 lbs. Not knowing the scales true accuracy, it looks like I am on the boarder of an option 3440 and 3450.

What do you think? By the way, the sash is 17 years old, but the reason the balance failed is because the rivit pin used to hold the spring failed (pulled through the channel holes). Make sense?

Go with option 3450?
Profile picture of Paul
Paul from SWISCO responded:
February 27, 2015
If the original balance was 3440 and lasted 17 years, I would stick with that. 17 years is a long time for a balance!
5/8" Sash Guide, Norandex
5/8" Sash Guide, Norandex
18-161
$1.88
35" Series 380 Channel Balance
35" Series 380 Channel Balance
S380-35
$12.05
How to Repair a Jammed Window
How to Repair a Jammed Window
VIDEO
WATCH >
How to Replace a Top Sash Guide [1080p]
How to Replace a Top Sash Guide [1080p]
VIDEO
WATCH >
How to Replace a Non-Tilt Channel Balance
How to Replace a Non-Tilt Channel Balance
VIDEO
WATCH >
How to Identify Replacement Channel Balances
How to Identify Replacement Channel Balances
VIDEO
WATCH >
How to replace a non-tilt channel balance
How to replace a non-tilt channel balance
GUIDE
READ >
Choosing a Non-tilt Channel Balance: What Will We Need?
Choosing a Non-tilt Channel Balance: What Will We Need?
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.