block and tackle

Question

Hi, can you tell me which of your block and tackles is a replacement for my 28D? I have used 2820's but they don't have as strong a spring.

Casey · Accepted Answer

Hi, The 28D is typically replaced with 2840. To check remove the sash and place it on a scale. *Stamp option 2840 will carry a window sash weight range of 23 to 28 lbs.

*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.