correct part number?

Question

Hello,

I'm trying to replace the window balance, but ran into an issue. The balance is stamped with 18C (which I believe it also translate to 1830) but the length of the channel is 29" not 19" as in product S385-19. Will this be the right part? the half of the window been raised is 31x51 single pane.

thanks for the help
Bismarck

Casey · Accepted Answer

Hello, thank you for writing in! When determining the length of your channel balance, be sure to measure only the metal channel and do not include the plastic attachments at either end. If you have the Series 385 and the channel length is 29", then I would weigh your window sash and consult the chart on the S385-29 product page to determine which spring strength would be appropriate.