I just made my first square reamer yesterday. I built a trade gun a few years ago and made the barrel from DOM tubing and reamed it with an adjustable reamer but I was never happy with the bore. I am going to try this reamer on it this weekend.
I started with a piece of 5/8 O-1 drill rod. I hardened it last night by embedding it in a square steel tube filled charcoal and heating that in my muffle furnace to 820 C. I quenched in a mixture of DOT3 brake fluid topped of with power steering fluid to fill my quench tank. Turned out nice and hard and perfectly straight. I have it in my kitchen stove now to draw the temper. I am excited to see if this works.
Rex
