Single hung 2720 balance spring

Question

Can u please identify the metal tab encircled in red on the attachment of this single hung 2720 balance spring? Said tab is missing from the opposing side spring.
Also what is the purpose of this square metal tab. The wind blew the lower sash off causing window breakage.
Do u sell these unique springs with this tab?

Thank you-Charlie

Jasmine · Accepted Answer

Thanks for reaching out! The metal tab you are searching for appears to be a balance retainer. It helps to secure the balance and prevent it from shooting up out of the channel, especially when removing the window. There is a chance that we can supply you with a replacement for your metal balance retainer, but I'll need a bit more information to confirm.

To start, may I see a photo of the clip removed from the window channel? It would also be very helpful to see a photo of the space where the clip is installed.

To be able to identify the right replacement balances, I'll need to see a photo of those removed as well. I'll need to see clear photos of the top and bottom attachments of the balance to confirm the right series. The stamp from the balance is only used to determine the weight range your balances should be able to carry to support the weight of the sash.