Ivan,

If it fits together as I assume it does from your photo, I think I'd be inclined to fashion a new holder from fresh material that was easier to work. I can't see, from limited experience using my small shaper that it needs to be hardened to the degree that yours appears to be, unless its intended use is towards the industrial end of the work envelope.

John

I've just machined 1.5mm off the bottom of a couple of hard Sandvik lathe toolholders using a replaceable carbide tip face mill, one of the Arc ones, no problem at all. Very hot blue chips though so wear your safety glasses!. Surprisingly good finish as well, I've also done similar with a Glanze face mill from Chronos, did the job ok but the finish was not as good, the Glanze inserts never seem to be up to much, I now buy alternatives from Ebay that cut much better.

Dave

Sacrifice a little bit at the end with an angle grinder to see if it's all hard or just case hardened. I'd make some angles 4 or 5 mm long to expose the core and try it with a file or hacksaw to verify whether it's hard or not. need to take the corners of the angles out too to expose the core.

From what I've seen the base material is generally pretty obdurate an any serious hardening is concentrated on the top where the holding bolt goes. Base material is still tough enough to give an end mill a hard time. I find my Elliot 10M shaper does better.

A good carbide end mill should handle it just fine. If the angled cut test mentioned above shows it is case hardened starting the cut where the softer material shows will give the cutter an easier time.

Clive

Grind off thee faces with an angle grinder,just leave hardened and flat the face that locates in the lantern toolpost,a grinder disc is far cheaper than ruined carbide cutters.

Orientation B is correct but your toolbit is sloping the wrong way. You want the face of the tool approaching the work to be angled back, akin to positive rake on the top of a lathe cutting tool, as per A. In orientation A the bolt holding the tool takes the full cutting force rather than the toolholder body.