Casey from SWISCO responded:
April 23, 2009
Looking at the stamp as 15-1 it could be 1510 option but looking at it as b 15 it could be 1520.
Weigh the actual window sash. 1510 will carry a window sash load of 4 through 6 pounds, a 1520 will carry a weigh range of 6 through 10 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. |
Casey from SWISCO responded:
June 8, 2009
Most likely the 1520, to check remove the window sash and place it on a scale.
A 1520 will carry a window sash weight range of 6 through 10 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. |