Thread: harden cast iron

Yes it can.

Problem is that once hardened, it's likely to also become quite brittle, and somewhere that's going to see the odd shock or two (like a tool rest) may decide to snap just for the fun of it.

What about a steel one? A bit of angle iron works well as a rest, and whatever is needed underneath welded on should be fine and cheap too.

Hi hazard,
Sure you can harden it, just weld on it and dunk it in water.That action will also wreck it.

Cast iron is not at all like steel and has different properties. There are hard forms of C.I. but they are manufactured like that. There are half a dozen forms of the stuff . The hardness quotient is derived from the alloyed make up more so than heat and quench ,which is probably what you are thinking about.

There is no doubt at all that is you apply heat and quench you will create unwanted results.

If you can't live with the tool rest get one fabbed out of steel.

Grahame

Gidday

Need a bit more info here...Cast Iron is already very hard resistant to scratching etc But rather brittle..................

We snapped some with a hammer in a vice as part of learning about the mechanical properties of metal at trade school! Go to scratch it with a scribe or mark it with a punch n shes a different propersition altogether!

What did you want to use and harden it for?..............

REgards Lou

Sorry I am late getting back on this forum. The tool rest supplied with my secondhand lathe is appears to be very soft and marks at the slightest inexperienced snatch and catch that I make in my efforts to learn to turn. The marks then foul up my nice smooth skew chisel work and result in another catch and so on. A smooth tool rest must improve quality of cut? Regards Hazard

Hazard,
The tool rest is a dead easy thing to fab.I have made quite a few of these tool rests.

They consist of a piece of round bar welded in a tee configuration to a piece of flat bar say 50 x10 for rigidity.

The round bar diameter suits the hole size that the tool post sits in.
About twenty minutes work if you know someone with a welder.
Grahame

Hazard, also knock the sharp corners off all of your lathe chisels, scrapers, etc with an angle grinder, file, emery cloth, whatever. Just the very corner, don't go overboard. This will stop them scarring the rest.

Will make a big difference. I had the same problem with my mild steel toolrests.

Finish by draw filing the toolrest smooth, & scrape a paraffin candle along to make the tools slide easier.


Cheers.................Sean

Thanks all. As usual the forum gives good sensible advice. Regards to you all, Hazard

You can also use a length of straight rectangular solid bar for the rest, ask the welder to run a bead of 'hard face' rod down the working edge & it won't nick.