Casey from SWISCO responded:
November 17, 2009
The 3600 has a different weight tolerance than the 3601 option. It is best to replace to the original stamp and use the intended strength balance.
3600 will carry a window sash weight range of 9 through 24 pounds 3601 will carry a window sash weight range of 25 through 32 pounds Sash weight ranges do not include the manufacturer's sash friction from use of weatherstripping. This friction must be verified by the manufacturer since all windows vary in sash friction due to manufacturing methods and weatherstrip types. |