On Sep 24, 2:50*am, "Michael Koblic" wrote:
....
The experiment is to be repeated with some changes and bona fide mild steel.

--
Michael Koblic
Campbell River, BC

In my experience scrap-yard mystery metal and some hardware store CRS
machine considerably better after annealing. Often the quickie 'water
anneal' is enough; heat it red, quench when the glow disappears.

Milling or filing a flat makes cross-drilling easier, at least until
the bit breaks through and grabs. A few times I've used a center drill
beyond its intended depth to make a parallel-sided starting hole.

jsw