Stamp on balance

Question

I'm preparing to order new balances Item #S380-26, but I'm not sure which stamp option to use. The balances I'm replacing are stamped 25 5 with (in much smaller letters) BSI RM. Would this be the 2550 stamp option? Thank you.

Casey · Accepted Answer

You possibly need the 2550 stamp option. To check, remove the window sash and place it on a scale. A pair of 26" Series 380 balances with stamp 2550 will carry a window sash weight range of 25 through and including 28 pounds.

This information is based on 2 balances per sash. Balances are designed assuming friction in the jamb weather-strip will carry a portion of the sash weight. Suggested sash weights are approximate.