Identify correct spring balance

Question

1) 1/2 inch metal channel. The metal channel measures 22 inches but stamped on the channel is: 21 12BS1 (I believe the 5th character is a B but could be an 8) See photo 001.

2) I can't show it installed because both came out. String is broken in one and the single roller bracket is bent in the other.

3) There are no square holes in my window frame to insert the clip. Which of the three round holes do I use. See photo 007.

Bob · Accepted Answer

Thanks for writing in, Ralph. This looks like a S351-22 or S390-22. The only difference between these two balances is the 'depth' of the bottom nylon shoe, so compare both with your old hardware to see what matches best. You will need a stamp option of 21 12 is a little unusual to us. We recommend you weigh your window sash. You can then match that exact weight with one of the weight ranges listed alongside each stamp option on the product page.

As far as your take-clips go, these holes are little unusual and don't match the configuration that matches the 16-002. Did you have a different kind of take-out clip? If so, it may not be anything we can replace unfortunately. Your best bet would be to install screws on either side of the window track, which can then catch the balances during removal and replacement. Let us know what you think.