Adjustment

Thank you for reaching out to us. The 84-502 adjustment screw is used with the 84-066 roller assembly. However, you should have an existing screw in your patio screen door that you should use. I wonder if you have the 84-074B instead. Look over the specifications and compare them with your old hardware to see what you think. 

The 84-066 has an elongated hole to allow the 84-502 adjusting screw to pass through. The adjusting screw actually screws into the door frame and holds the position for adjusting the 84-066 roller.

I'm glad we could help. Good luck with the repair!