it's a steel screw riding in aluminum threads in the housing.
Here is how the MGW pushers are made. The main threaded shaft, screws in and out of a threaded STEEL bushing that is (threaded in side and out side) Screwed in, jammed and loc'tited into the aluminum body. The main shaft is also threaded internally with a left handed thread pitch for the support shaft that rides inside the support hole in the body on the right side.
Any lubricating oil will work on the threads. Do not use WD-40 because it turns into a thick nasty varnish over time.
MGW tools are the best, I have some that are probly 20 years old. I have also modified several to fit other guns as needed. If anybody has any questions about MGW tools let me know, even if you need spare parts... I got a couple of boxes full of MGW tools and parts.
Some sights it doesn't matter if it goes in right to left or right to left. Not all guns are the same, as the same as different sight makers put lead-ins on the dovetails on different sides of the sight. **** Look at the sight to verify**** I like to start sights by hand and visually look at them to make sure they are seated in to the bottom and centered.
Don't screw up your gun or sights by being careless. AND ALWAYS fit the sight to the gun, never alter your guns dovetail unless you know what your doing. Even then I wouldn't do it.