Replacing wood window baalnces

A home owner from Huntington, NY says:

I am trying to repair four old wooden double hung windows in my garage. The windows have been inoperable for years.

The mechanism for each window is some sort of spiral spring balance but they are all either snapped in two or severely rusted. The lower sashes are 12 pounds each. The top spring section of each balance, (which was once covered by a plastic or vinyl covering that has cracked and broken off each spring) is 27 inches long and 1/2 inch wide. The remnants of the plastic or vinyl covering the springs were 5/8 inches wide.

I've attached pictures of one of the balances. The top part of the balance is screwed or nailed into the top of the window jamb. The bottom of the spiral part of the balance runs down the side of the sash in a channel and wraps around to the bottom of the sash where it attached with small nails.

Could you tell me if any of the spring balances you sell could be used to replace these old balances in these windows. The pictures of the new balances I saw on your site all seemed to have a connector on the bottom of the spiral part that I wasn't sure could be used with my windows. Any advise would be appreciated.

Thank you,
User submitted photos of a window balance.
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Paul from SWISCO responded:
Our Series 500 spiral balances have been used by wood window manufacturers since the 1940's. The tube has a diameter of 5/8" (or 9/16"), so if yours matches I think it's a great choice.

You said the top sash balance was 27", so see our S500-27 with the 17-012 bracket. For the bottom sash order S500-29 with the 17-012 bracket. Instead of using nails, I would use screws like our 33-017 to fasten the balance tube at the top and the 33-088 for the bottom bracket. You might want to also see our 75-004 charging tool to wind up the balances. See the link below for more information how this works.
A home owner from Huntington, New York says:
Thank you very much for your response, Paul. Just one point of clarification; the 27 inch number I referenced in my first email is the length of the spring mechanism (not including the spiral portion that retracts into the spring) that attaches to the lower sash. The upper sash is fixed and I plan on leaving it that way. The upper sash is 27 inches high and the lower (operating) sash is 28 inches high. I assume the S500-27 is the proper replacement balance to buy to replace the old 27 inch balances, but if I should get the larger ones please let me know. Thanks again.
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Paul from SWISCO responded:
Oh, my mistake. In that case, yes, I think 27" for the balance is good.
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