Inductive heater

[Vinny]

I also bought one a few years ago from China. Yes, the pump pumps water thru the coil. For a power supply I bought a 20A supply from some other Chinese vendor really cheap. I *still* haven't tried it out. Heat treating is exactly what I bought it for. Somewhere, probably here, I read about a company using an electromagnet to hold parts in the air as they passed thru the induction heater. When they were hot enough they were no longer held by the magnet and dropped into the oil bath below. I was thinking something similar on a much smaller scale.

[Highpower]

If all you want to do is harden small cutting tools then the induction heater will do.

But I think you would be better off building yourself a furnace so you can hold larger/thicker items at temp to soak them. When I had my small muffle furnace torn down to convert it I was surprised by how simple they really are. The second part I wanted to heat treat was too long to fit into the small furnace of course. Since then I bought most of the stuff needed to build a second (deeper) furnace. The insulating brick was probably the most expense. Other than that it's just a frame/case, some heating coils, a cheap PID controller, solid state relay and a thermocouple.

As usual finding the time/desire to put it all together now has been my biggest hurtle. New projects keep pushing back the old ones.

[Vinny]

My idea, when I bought this thing, was making wood turning tools. The actual tool part woulda been drill rod then a 1018 holder onto a wooden handle. Still may do it.

[Highpower]

Coming back to this thread on induction heaters I had a project in mind but can't decide if I should attempt it or not.  

I bought one of these hardened and ground truing arbors with the intention of turning down a portion of the 1" shank to 3/4" so that I can use it in my mill. My first mistake was assuming this was a through hardened piece of material. It is not. AFTER I bought it, I find out it's is a piece of 8620 that has been case hardened .020/.030 deep to 52/56 Rc.  30 Rc. Below case.

   

After my last encounter with hard turning (linear shafting for my shop microscope stand) and eating up 4 or 5 normal carbide inserts to get it done, I pried my wallet open and ordered one single CBN grooving/turning insert from MSC to the tune of $120. After several weeks of waiting it should arrive next week. I'll use this to remove the first 2 inches of case hardening and get down to the chewy nougat center. Once I get it turned down to 3/4" diameter I'll be left with a relatively soft shank. So... I have this induction heater and an original can of KASENIT.  

Left brain and right brain are fighting it out. Attempt to re- case harden half of the shaft for wear protection and HOPE it doesn't warp the other half - or just leave it the heck alone and take my chances that way?

I could have made one from scratch ( I still have some 4140) but I don't own a surface grinder. I thought (assumed) I was buying a through hardened and ground "tough alloy steel" arbor that I could simply turn down but Noooooooooo....

In hindsight I wish I would have contacted SOPKO and asked about the material before I bought the arbor. I do have to say they did an EXCELLENT job responding to my inquiry (a few hours) and gave me the detailed info above without hesitation. Superb customer service.