29 9 BS1 Balance

I'm not sure what you have, unfortunately. There are dozens of different balances with that stamp. It's not a product code or anything, it just indicates the strength of the spring.

In order to figure out what Series this is, I need you to remove an undamaged version of this balance from the window and show me clear pictures of the top and bottom nylon fittings. I will also need to know the dimensions of these fittings.

Thanks for your photos. Based on what I see here, you have either our S380-29 or S385-29, depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match.

As for sash weight, I recommend getting a more precise weight. Right now you might require the 2865 stamp option, which carries 35 through 39 pounds, but you never want to make that decision based on an estimate. Take it from someone who had to learn the hard way: you want to be as precise as possible. 

Comparison of the S380 and S385 balance shoes.

Great! I'm glad that our S385-29 is a match. 

All orders can be placed directly on our site at your convenience. Just let me know if you had any other questions.

Like I said above, all orders can be placed on our site at your discretion. You can just visit the store page for the S385-29, which is linked throughout this thread.

You're welcome! Please let me know if we can be of any further assistance and we'd be happy to help.