need three different sized window slides

Question

Dear Sir or Madam:

The numbers stamped lengthwise on the slides are, from shortest to longest, 1520, 2020, and 22B. Each slide has "B.S.I." stamped across its width, in tiny letters, to the right of the number.

The spring broke in each of these. The windows from which they came were old when I moved in 22 years ago. Someone suggested that they are Capitol windows and the slides come in right and left pairs, but I am not certain that this is the case.

Some of your parts look similar to these, but do not match exactly.

Can you suggest replacement parts that have a good chance of working?

Regards,
Mark

P.S. - Please let me know if you need additional photos.- M.S.

User submitted photos of a window balance.

Tom · Accepted Answer

Hey, thanks for posting. I've narrowed these down to two possible channel balance Series: either our Series 351 or our Series 390.

Now, as you can see, the only difference between these two Series is their bottom shoe. The Series 351 uses the 15-002 while the Series 390 uses the 15-001. I can't quite tell what you have based on your pictures, though. Please carefully compare their dimensions to your own hardware and see which is a better match.

Comparison of 15-001 & 15-002

Once you've settled on a Series, you can then select the appropriate lengths and options.