Part for single hung aluminum window

Question

I have a 60's series window balance (2920) that came out of the window last night. The balance is fine but the part pictured is broken. I looks like some sort of cam stop. It is screwed directly into the window.

I don't know what part to order to replace.

Can you help?

User submitted photos of window hardware.

Paul · Accepted Answer

This looks a lot like our 18-168. Check it out and see what you think.