One-each Jr HS, HS, College chem labs, all "team" efforts.
Then already packaged "thermate" Corps of Engineers far more often than mere "illustration". Field use. Scrap tanks and such as training materials. I was a student. Then an instructor.
Could was it was "inch" actually. I did say "equivalent to 50 millionths", so that's only a tad under quarter "tenths". I were too ignorant to know about metric. Pelz being Schwabian but US based 1921 or 1923 onward, he was actually agnostic, used inch or metric without a second thought.
Mauser, BTW, had the "rotunda" brand on it, same as our rifles to-home. I think those were actually MADE by Georg Mahr? And it cudda been for US market, as Mauser were kicked out of the weps bizness and looking for any way they could use the name to earn a crust. Swiss outfit owns the Mauser name for firearms recent years.
I last laid eyes on that grinder around 1974. Had USED it during an overly-long IBEW strike. Management all having come up off a shop floor "somewhere" we kept the hard-of-hearing, hearing, just couldn't ship much NEW.
Talk about GOOD? Pelz had me make a fixture, mostly on the B&S, then use it to crank out 800 tiny ten-thou blade screwdrivers Starret store boughts could not get into the same room with. Got 780 good ones, heat-treat losses, mostly.
Over a dozen years on, by '74 they were all gone, and that fixure misplaced or scrapped. Made a new one from memory. Strike over, there's Karl Wagner turning that thing over and over. "I knew this was your work the minute I saw it. There will be those damned blind dowels with the counterbored and upset ends you always made rivets out of to hide from view!"
"Never meant to take food off your plate, Karl. Make a new one, and do it right. I didn't have TIME for dowels of any kind."
Flung it on the floor.
The crazy-glue joints between those perfectly ground B&S #2 surfaces let go, and it was just a collection of loose junk! Didn't want to risk a Bargaining-Unit person's safety on crazy-glue!
As to HOW?"
Herr Pelz was about 74 years old around 1960. His own Dad (and the gal he was to marry's Dad) where "uhrmachers". He was apprenticed to Diamler, age 14, so about 1900?
Earned his Master's ticket during early World War One, maestro of the hand-fitting of six-cylinder Mercedes aero engines for Kaiser Bill's air force. Speciality? Hand scraping the Bronze camshaft bearings! Selecting, matching, and fitting the Cast Iron pistons.
Far too late to ask HIM!
Or my NEXT Grand Mentor. George Mortimer had come out of retirement when his wife died. Was 81 when he stayed-over off first shift to see who TF was this "kid" cutting his tolerance in half on an Aluminum Bronze part nobody on the payroll but George was supposed to be able to turn
at all.
Talk about "instant adoption"! Watched me setting up. Vanished over to his leather covered chest. back in a flash; "Here, keep this!" GIFTED me with a TINY, and already old but perfect (still is) Starrett "Last word" DTI.
F**ks sake. Standing there in a pair of steel toed boots as were to be five whole US dollars out of my first paycheck. 'Coz I didn't YET own five whole dollars!
I put it reverently into my Kennedy and went back to dialing-in with a dental mirror and a sharpened darning needle. Job done, I turn to see a huge false teeth grin!
"Bill, you can do THAT on the junk we run here, you can turn out good work anywhere in the whole world."
And I had me another great teacher!
Mind.. I had done six of those in 8 hours. George had done TWENTY four or twenty six on HIS shift! Same old Niles!
I did say "teacher?"
Pelz had spent over a WEEK on that B&S. And he were sort of a "magician, tenth dan".
You've got yerself a "project" but done right, that old B&S will hold DAMNED GOOD for a helluva long time afterwards. Too straightforward simple to be bothered doing otherwise.