I picked up the O-1 drill rod for makeing tools.

I thought that I'd try makeing a serious gun out of 4140.
I took the 1 1/2" O-1, cut a slice off of it, bored and brazed onto a 1/2" grade 8 bolt, then turned down to true up and shape, then cut teeth and hardened in oil. It cut great on everything except soft O-1. I tried useing it to cut the flutes on my 30 Erin reamer. It cut one flute then went dull. So I finished it with a carbide endmill.

Lar,
i am thinking of 4140 or 4340 when i get around tuit...

I have made several tools and knives from o1... it's genereally soft as hard plastic (well, it's harder, but it's soft) and use a 6" bench blet sander to do final shaping on the blades... pretty fast and easy.

jeffe

How much harder is it to machine the 4340 than 4140? From reading the description of getting leaded 4140 it sounds like it machines fairly easily.
Looking at the yield strengths, the 4130 isn't that much stronger than the grade B Structural that I made the 30 Erin out of.

sorry... i was wrong.. o1 is oil quench... had a cross wire on soething else

jeffe