Hello from Hudson Valley, what steel to use...

There's lots of steel all around. Just have to learn how to take apart things quickly when no one is looking :p
also being able to run fast is helpful.:D
M
 
From good old Wikipedia:

Induction hardening is a form of heat treatment in which a metal part is heated by induction heating and then quenched. The quenched metal undergoes a martensitic transformation, increasing the hardness and brittleness of the part. Induction hardening is used to selectively harden areas of a part or assembly without affecting the properties of the part as a whole.[1]

The interesting bit to me is that you could spot harden if you needed.
 
You are making bushings for a tail stock turret to be used in a small lathe in a hobbyist setting making threaded stand offs, a discussion of material selection and hardening is way overkill. If made from plain old 1018 available at Home Depot you will not live long enough to wear them out even if you are 20 years old now.

Last week on a Warner & Swasey turret lathe of WW2 vintage, 1 5/8" drill through 3 1/8 long steel parts in one shot, no peck and no pilot hole in less then 6 minutes each. Not a single one of the turret adapters is hardened either straight or tapered (several dozen).
Draw you own conclusions.

Sorry about the knee shot, I do not spend my days editing How To videos nor have the equipment and software to do so.
 
Last edited:
Turret lathe doing what turret lathes do best! I had a #4 Warner Swasey in my shop when I sold it and retired, and used it for a variety of limited production work. I particularly like spade drills for doing that sort of drilling, they break up the chips, and are NEVER used with pilot holes, perhaps just a spotting drill to start them.
 
For any steel or cast iron to respond to heat treat, it must have an carbon equivalency of at least 2. This number is derived from the carbon content in association with the Manganese content in the material. Any steel can be harden if this number was met. Of course, other chemicals added like copper, high contents of Nickel and so on, make it so , it will not respond to HT. When you do that, it reclassifies the steel into different categories of metals.

A place I worked at several years ago, we used to take 1020 castings and carbon restore into the surface of the steel. So when the parts were set up on the induction hardening machine, the surface was heated up and polymer quenched to give us a hardness of about 50-55 HRC. It would have been much cheaper to carburize the parts at the same time they were carbon restored. It was a political decision that came from upper management, our hands were tied!
 
4gsr said:
For any steel or cast iron to respond to heat treat, it must have an carbon equivalency of at least 2. This number is derived from the carbon content in association with the Manganese content in the material. Any steel can be harden if this number was met. Of course, other chemicals added like copper, high contents of Nickel and so on, make it so , it will not respond to HT. When you do that, it reclassifies the steel into different categories of metals.

A place I worked at several years ago, we used to take 1020 castings and carbon restore into the surface of the steel. So when the parts were set up on the induction hardening machine, the surface was heated up and polymer quenched to give us a hardness of about 50-55 HRC. It would have been much cheaper to carburize the parts at the same time they were carbon restored. It was a political decision that came from upper management, our hands were tied!
Click to expand...
I am not familiar with the "carbon restoration" process, please explain.
 
Glad to have all the info, gents. As a note, I will be on vacation for the next week, away from the lathe, but then should have a clear week to work on the tool holders.

Best - Peter G.
 
With out question, I would use 4140 PH, (pre-hard) this is about 30-35 Rc hard on the OD and softer on the inner area. The PH will give an excellent turned finish for .750 and the center can be drilled and reamed to the desired diameter.
 
Rick Berk said:
With out question, I would use 4140 PH, (pre-hard) this is about 30-35 Rc hard on the OD and softer on the inner area. The PH will give an excellent turned finish for .750 and the center can be drilled and reamed to the desired diameter.
Click to expand...
I like to add a little to this. What people call 4140 pre-hard is really 4140 Q & T (Quenched & Tempered) to 28-36 HRC. And in rounds up to 3" in diameter, it's fairly consistent hardness to the center of the bar, not just the outer area of a bar. And really, the higher heat treated material in my opinion cuts much nicer. It's tough drilling, but with good cutting oils/fluids, it's no different than cutting 1018/1020 material dry.
 
You must log in or register to reply here.
Back
Top