Ever since we ran out of virgin tool steel, carbide has become the status quote, making it super cheap due to mass production. And it does have its benefits.. rigid, higher cutting rates, better heat dissipation, longer lasting edge, blah blah blah.
But what about high speed steel? It's not so bad, it has its good points.
Semi flexable, able to have a sharper corner than carbide, resists chipping, and more forgiving on a crappy spindle, better heat dispersion, etc...
So the question is...is carbide always better? At least as far as end mills go.
I find myself going for the high speed steel mills when on the bridgeport. Iv'e yet to break one(not a cobb mill). I still have hss endmills in my box from 1986/1988 that will take as big a cut as I can crank the mill, even with a wrench on the handle. Yet I look at my carbide endmills from just 5 years ago or less and they all have tiny chips. Making them junk.
Seems we are switching to 100% carbide/diamond, but is that a good idea? A good example is high quality hand tools...they arent made of carbide or even hss, they are made of cold rolled steel. After heat treat they are hard on the outside, soft in the middle. Makes for a real strong, wear resistant, semi flexable, stable as hell tool. Best made tools in the world (herman Smidt) are all case hardened, to give the benefits of hardness without becoming brittle. Has anybody tried hss core with carbide outside, diamond coated? I know nitride coated has attempted to acheive this.
I just don't know why we stopped using hss on endmills, for some reason 99% of drills made are still hss?