Related Glossary Terms
- Rockwell hardness number ( HR)
Rockwell hardness number ( HR)
Number derived from the net increase in the depth of impression as the load on the indenter is increased from a fixed minor load to a major load and then returned to the minor load. The Rockwell hardness number is always quoted with a scale symbol representing the indenter, load and dial used. Rockwell A scale is used in connection with carbide cutting tools. Rockwell B and C scales are used in connection with workpiece materials.
Enlarging a hole that already has been drilled or cored. Generally, it is an operation of truing the previously drilled hole with a single-point, lathe-type tool. Boring is essentially internal turning, in that usually a single-point cutting tool forms the internal shape. Some tools are available with two cutting edges to balance cutting forces.
- computer numerical control ( CNC)
computer numerical control ( CNC)
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
Turning machine capable of sawing, milling, grinding, gear-cutting, drilling, reaming, boring, threading, facing, chamfering, grooving, knurling, spinning, parting, necking, taper-cutting, and cam- and eccentric-cutting, as well as step- and straight-turning. Comes in a variety of forms, ranging from manual to semiautomatic to fully automatic, with major types being engine lathes, turning and contouring lathes, turret lathes and numerical-control lathes. The engine lathe consists of a headstock and spindle, tailstock, bed, carriage (complete with apron) and cross slides. Features include gear- (speed) and feed-selector levers, toolpost, compound rest, lead screw and reversing lead screw, threading dial and rapid-traverse lever. Special lathe types include through-the-spindle, camshaft and crankshaft, brake drum and rotor, spinning and gun-barrel machines. Toolroom and bench lathes are used for precision work; the former for tool-and-die work and similar tasks, the latter for small workpieces (instruments, watches), normally without a power feed. Models are typically designated according to their “swing,” or the largest-diameter workpiece that can be rotated; bed length, or the distance between centers; and horsepower generated. See turning machine.
I’m not a morning person. If it were up to me, all alarm clocks on Earth would be rounded up and smashed with a giant hammer, their electronic corpses left to rot in a landfill far, far away from my home in Tucson, Arizona.
I’m not sure what people on other planets do about the whole alarm clock situation, but I assume they are more advanced than humans and therefore late sleepers like me. Unless my dad’s predictions about the looming extraterrestrial invasion are accurate, however, we’ll never know.
To be honest, I don’t need an alarm clock anyway. That’s because I have a wife, one who’s A) an early riser and B) quick to point out my many flaws, particularly my reluctance to roll out of bed before noon. There’s also the fact that I am now a freelance writer and no longer need to be in my car before the crack of dawn, sucking down my third cup of coffee while counting the days until retirement.
Back when I actually had to work for a living, though—oh, boy. I was late all the time. I can’t begin to count how many times I received a dirty look from my boss, was caught and scolded by the shop foreman as I sneaked through the shipping department in an effort to reach my CNC lathe undetected or was actually written up by Brenda, the smarmy human resources gal who was clearly another early riser, just like my wife.
All this for strolling in a couple of minutes late.
I’m sure that none of you cares about my sleeping habits, but I bring this up because of something I read one morning (while still in bed, thank you). It seems that Elon Musk, Tesla Inc.’s chairman and CEO, has instituted a new attendance policy. After laying off 4,000 workers to try to make his shareholders happy, he or one of his brainiac HR peeps (I’m guessing that Brenda found a job there) invented the term “attendance occurrence” as a friendlier way of saying, “You were late again, dummy.”
Musk warned his surviving employees that arriving to work one minute late would result in a 0.5 attendance occurrence and that nine such occurrences would end in termination.
Yikes. One lousy minute?
All this from a guy who never punched a clock in his life, someone whose response to being stuck in traffic is to start a tunnel boring company and who launched a $112,000 Tesla Roadster into space. If I’d had that car for my daily commute rather than a rusted-out Ford F-150 that wouldn’t start when it was cold out, my attendance record would have been perfect.
In all fairness to Musk and Tesla, I get it. It’s a business, and when you have tens of thousands of employees, you can’t rely on dirty looks from the foreman to keep tardiness under control. Still, it’s important to remember that there’s more to an employee’s value than how many attendance occurrences he or she has racked up this month.
As for me, I’m going back to bed. All this talk of rules and regulations has made me tired. And my apologies to the editor for this blog post being late. I overslept.