chuck fired this volley in news:93657769-d75e-
:

I need to cut 5" circles out of 1/2" steel square plate. I will have
to bore a 1" hole in the center.
Whats the best way to do this with a lathe.

Didn't you just ask this, and get answers?

Cut a bunch of 5.25" square plates. Knock off the corners, too, to
save lathe time and interrupted-cut frustrations.

Drill the center of each. Stack all the plates on a 1" bar, with jam
nuts at each end to tightly clamp the plates together into a "solid
rod" of octagonal blanks. It can't hurt to loctite all the disks
together. Heat will re-separate them when you're done. It also can't
hurt to cut a small "hub" for at least one end, to ensure they stack
exactly square on the rod.

Turn to size between centers, or between the headstock chuck and a
tailstock center.

It sounds like a lot of setup, but goes very fast once the tools are
made.

Or, you could just have them cut on an abrasive water jet machine, or
a honkin' big laser cutter.

LLoyd