How to fix window that won't stay open/what is this part called?

Question

I've got single hung windows that don't stay open. They are the balance bar type not the weights in the jam kind. I took one sash off and found the following part is broken on both sides.

This is what my balance bar looks like, it doesn't seem to have any problems with the string or spring. I just include it to help people identify what I've got.

One more clue is that on a good window I can see the top of the part that is broken on the window that doesn't stay open. Here it is.

I'm searching but can't find a good replacement for that piece. I think a big contributor to my failed search is I don't know what that piece is called. Does anyone know what that piece is called and better yet where to get them?

Answer 1

This is the modern equivalent of a sash weight.

Yours is either a (window) spring balance or a spiral balance.

But you seem familiar with the terminology, so the real question is: what's that little plastic part called?

It's either a Nylon Sash Cam or a Shoe Set I think.

It might just be easier (and better) to purchase a whole Window Channel Balance Repair Kit and replace all the plastic parts. They're like $5. Then again, an entire balance costs like $10.

Answer 2

Not an expert but I did replace a broken window balance. I bought the part from this site. http://www.swisco.com/ this additional link may help you find the part you need. http://www.swisco.com/cl/Sash-Support-Balances_Hardware

You can call them and tell them what you have and they will guide you through their site and see if they have the part you need. you can also take pictures of what you need and send it through their site and they will get back to you too.