S900-29, but has 1/2" diameter

Thanks for posting! You may have our Series 600 spiral balance instead, whose tube diameter is 5/8" thick (or 9/16", which is considered 5/8" in the trade). Could you recheck the diameter of your balance and see if that might be closer to what you have? If it is, you may need an S600-29. Let me know.

As for the yellow-tipped balances, could you please give me the weight of your sash? This will help me determine the best possible color tip option for you, as the color tips determine what your balance's weight capacity will be.

Thank you. If you were to go with the Series 600, I would choose the blue tip. An S600-29 with a blue tip can carry a sash weight range of 12 through 31 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.

Now, our spiral balances do have a seam in the tube. I do not think this should be an issue, though. The way you described the damage to your balance makes me think that perhaps the sash was too heavy for your spiral balance's weight capacity. What I mean to say is, the spiral balance split like a banana under the strain of holding up the heavy window. I do not believe you will have that problem with the blue tip.