sliding window track

Question

Trying to find this track for older windows. There are not may markings but on the steel track where the string attaches to balance knife shoe there is the number 20 stamped.
If it helps, I have purchased the following to use in the track.

Balance knife lock Shoe
15-014

Please let me know if have anything like this track or if you need any more information

Bob · Accepted Answer

Thanks for posting. This might be a Series 751 Channel Balance, but to confirm it would best to remove the balances and show us pictures. You'll also want to confirm the length of the metal channel. That stamp option is a bit unusual too; can you give us the exact weight of the window sash? That would help move this along. Many thanks.