I have a Mac half-horsepower die grinder that I've had since the mid-'90s. Far as I know the premium Mac die grinder(s) were made by SP Air in Japan.
My elderly Mac sure looks like what I see in the SP Air catalog as the SP-7220, at any rate. I was just on the Mac web-site, and I don't see an aluminum-bodied die grinder like mine any more.
My Mac has hundreds if not thousands of hours on it, carving all sorts of plate- and sheet-steel (and some little bit of cast iron) using either rotary files or abrasive cutoff wheels. It went back to Mac for service once, and I put bearings in it myself once.
The company I worked for supplied "die grinders" for us to use. These were ordinary CP and IR grinders (Not "mini" die grinders) and this Mac would
destroy them for torque.
Again, far as I can tell, for a hundred dollars American you can get an SP Air Made-in-Japan grinder just like the wonderful one I have, from Amazon. More, I suppose, in Canada.
https://www.amazon.com/dp/B002O4WR8S/?tag=atomicindus08-20
I also bought a used Snap-On
long-snout die grinder similar to, but older than the current-model half-horsepower PT200AL. I like it very much. I don't care for the plastic housing although I can't argue that it's easier to hold onto than the aluminum of my Mac The Mac gets terribly cold with all the air rushing through it. The plastic housing offers some insulation. I learned to really appreciate the longer housing of the Snap-On for cylinder-head porting. Using two hands makes it easier to control than my Mac. The Snap-On guy gave me three more Snap-On half-horse die grinders that had failed and been traded-in. I had to replace the collet nuts on all three, and I pulled 'em apart for cleaning, lube, and inspection. They all work to varying degrees, but the molded-in threads in the plastic housing that hold the grinder together are weak on the ones I have. The Snap-On and the Mac have similar power, which is to say that they
totally kick-*** on the common CPs and IRs.
Yes, the one-horsepower Snappy looks attractive. I don't grind like I once did...but even so, there may be one in my future. I can't decide if I want the long snout PT400L, or just the regular PT400.