Perfect machining

[Toolmaker51]

Not uncommon to offer varied levels of precision; appropriate to the end user. We often have to lift their standards, usually when they think 'anything will do'. The usual job shop calls the shot maybe half the time.
Making tooling or repairs for knowledgeable customers is far easier; they understand overhead and costs involved.

It's the guy walking in, "it's just threads", a bearing fit, a crummy casting to duplicate, that's shocked by cost.
Well; go buy yourself a lathe, tooling, only stuff to make THIS project. . . then a building, electrician, riggers, business license, property tax.
Allow time to learn how to do "just threads. . ."

[Ricklesss]

I've heard "rumor's" of machinists measuring things in millionths of an inch.
I've always wondered if that was actually true. Also, I always wondered how someone would measure something like that.
Maybe these videos are an example of tolerances like that?
RicklesssS in Oregon

[PDXsparky]

Indeed, the Chinese do make some pretty high quality goods, but they don’t export much of them.

[Frank S]

Indeed, the Chinese do make some pretty high quality goods, but they don’t export much of them.

Actually they do but most of what is imported into the USA and several countries in Europe and the middle east are imported by those who are trying to capitalize on the lowest prices they can. If you want to get the Higher quality goods from any country you have to actually go there then search out the manufactures or the high quality goods yourself. it is not any different that US goods being sold in other countries if a person is in say Spain and wants to buy something made in the USA at a local establishment they might not be purchasing the same quality as can be purchased here the item might even be made to a higher standard or a more relaxed less costly standard , Not every manufacture makes one specific grade of goods some manufacture varying levels or specific models for export only this is done to target the market place and to compete with other manufactures in which ever particular region they goods are being sold.
And many manufactures are international. There was and may still be a hand tool line called Spiero at one time I had some combination wrenches by that brand which were made in a multitude of countries forged right into the tools were places like Germany Spain USA China the packaging they came in clearly stated the country of origin Over in Kuwait we imported and sold them in our showroom in displays depicting the countries you couldn't tell one wrench form the other if it were not for the stamping

[greyhoundollie]

Back in the day when I was a kid I went to a large machine shop where every man there was of the exact same opinion as you high side. Once a month or so the men would have a contest of fingering the measurement of a few metal pieces and writing down their findings on a piece of paper then turn their slip in. Then the pieces were micrometer measured and results compared. The winner didn't win anything spectacular.....except.... the admiration of his fellow workers. Something that seems to have fallen by the wayside over the years. I think a mans micrometer was checked for proper calibration on a regular basis.

[Toolmaker51]

Calibration is a huge facet of traceability and ISO9001, despite ISO being somewhat a smokescreen.
Long Island Indicator Service - Site Search Results

The effective method of size control applies a four to one [4:1] accuracy standard against a specific tool. Say instrument 'A' has .001 increments, but the repeatability is .002; is not allowed interpreting size with any less then .004 +/- tolerance, [.008 total, or 4 x 2].
Despite being one favored instrument on parallel flats or diameters that can be spanned, vernier calipers are frowned on.
Accuracy is of critical importance to companies involved with the most important products on earth, loosely and publicly labeled 'safety devices'.

A shop of any size can/ should monitor personal tools through a properly equipped inspector or inspection department regularly. That's based on usage and time periods. It is tool owners responsibility to check his property often as tolerances get less range. Bigger shops maintain tool cages as means of calibration control, often the workers have no personal tools.

There is separation from monitoring to actual calibration by outside specialists. They maintain cleanliness and temperature better than within most any plant, to protect their investments in physical calibration standards, well above mere gauges. Naturally, that certification is not inexpensive.