Block and Tackle Window Balance

Question

I need help in identifying the specific part number for this item so that I may order two of them.  It is a block and tackle balance for a double hung window.  Measured from metal to metal, length is 30 inches. The width of the channel (inside width) is a little over half an inch.  It is stamped with 2917 BD .

Bob · Accepted Answer

This appears to be either an S380-30 or S385-30. The only difference between these two balances is the depth of the bottom nylon shoe, or the 'heel-to-toe' measurement, so compare both with your old hardware to see what matches best.

You'll then need to choose a stamp option, which indicates the strength of the balance. I'm having trouble reading your stamp, and the stamp code 2917 is not familiar to us. Please weigh the window sash that these balances support. You can then match that exact weight with one of the weight ranges listed alongside each stamp option on the respective balance's shop page.