Steel double hung window part

Home Owner from Detroit
Apr 12, 2024 4:34 pm
Hello, I just bought a condo in Detroit that has 18 steel double hung windows which are probably 40+ years old. They all seem to have a broken "rail" - the part on the side that glides the bottom half up and down, and helps the window stay up. The springs are very rusted, a string in the part is broken. I cannot see any identifier on the windows that name the manufacturer. There is a sticker with a Series and MST number though. Can you help me identify this part and how to get 40 of them? Thank you!
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2 Replies

Lauren from SWISCO
Apr 15, 2024 9:52 am


Hello, thank you for posting,
It appears you have either the Series 351, with a 15-002 bottom attachment, or Series 390, with a 15-001 bottom attachment. Take a look at the image below and measure to determine which balance you'll need.
Are you able to confirm the length of the metal channel excluding the nylon attachments along with the number stamped on the metal channel? Thank you!

Comparison of the S351 and S390 balance shoes.