Simple question ....how?

My guess is to use an angle grinder with a thin cutoff disc

Should I cool it as I cut it?

Should I cut it over a ten minute period with a 2 minute cool down between each 5 second cut?

Do I file it after with a hand file or angle grinder with a grinding disc?

Do I hold it in my hand or put it in the vice with soft jaws?

Does it matter?

Andy

NB I know I mustn't drop it!!

yes that will work

KEEP IT COOL!!!, it might not be hardened all the way through so pour some water on it, let it draw the heat away and cut again

yes go slow and take many small cuts

a file probabaly wont touch it, use a bench grinder or an angle grinder

OMG dont hold it in your hand!!!!! us a vice or clamp it to a desk

yes it matters!

yeah dont drop it!

Hello,
I cut hardened steel shafts with a 300mm grind cutter. The disk is 3 mm thick. I cut a 16 mm in about 30 seconds without cooling. After cutting, I quench its end it in water. As you can see in the picture the heat affected zone is about 3 millimeters, quite negligible, since this section will be held in the supports and has no contact with the bearing. Cutting 25 mm shafts also had the same result.

Nader

That's reassuring.... thanks

I often have to cut stainless nuts from stainless bolts on the job. I use a very thin abrassive cutoff disk chucked in a cordless drill. Held very firmly I can slice through a nut and 3/8 bolt fairly quickly. I have applied the same scheme to cutting hardend rod using my drill press. I chuck the cutoff disk in the drill press, run it at medium speed, put the rod in the cross slide vice, and slooooooowly feed the piece through the spinning disk. Often is still cool enough to handle after cutting, and a nice smooth cut.

Steve

Surprisingly enough a dremel cutoff disk works well with no quenching required. I believe the disks are about 1MM thick.

I did this with 1/2" precision hardened rod, took 1.5 minutes.