Roundhouse Machine Screw Hole Help

[Trucklover]

Thanks guys, i think this is most likely what ill be doing, is doing 2-56 screws. Im not sure if thats what these screws i have is or not though, how do you know?

Here is a pic of what im talking about, as you can see, this is as far as the screw will go into the whole for the coupler mounting hatch, and its the same for the truck mounting hole as well. I was only able to turn it at the most one full rotation in the hole before it would not turn anymore, even with force.....