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Ronno6:
A guy advertised machine shop work on the local FB
I asked him how I would go about getting a quote, and ASKED him what tolerances he could work with........
He said to send him a sketch w/dimensions, and NEVER replied about the tolerances.

So, I sent him pictures and dimensions for a couple of parts, specifying +/- .001", 125 micro inch finish........
From my mechanical purchasing days, those were STANDARD commercial tolerances........
He about had a cow!!
Said he couldn't work that tightly.......
So I reminded him that that was maybe the SECOND thing I asked..............

He has gone away now in short, sharp, jerky movements.......
Or, maybe he flew around in ever decreasing circles til his head flew up his own..................

Ronfiveo:
I worked in a machine shop for years and if I remember right, +/- .005 with a 125 machine finish was
the standard for ordering a production part that would be on a mass produced scale.

However, +/- .001 could be ordered on a higher price scale. That's close to a
press fit. The higher price would be to cover the unavoidable higher scrap percentage.

And a 125 finish is standard machine finish, but a 63 finish is very shiney with less tool marks per inch, and a 32 finish
was like chrome or glass.

Or is it the other way around. It's been 40 years. :D

It's been a very long time but you brought back some fond memories.

Ron

pan60:
to funny when i am doing mic parts we hold way tighter then those.
i am currently doing a item and holding +/- .0005
:)

Ronno6:
He was advertising CNC work.
I wold think that +/- .001" would be slop work for CNC........

nced:

--- Quote from: Ronfiveo on February 20, 2024, 05:08:09 PM ---I worked in a machine shop for years and if I remember right, +/- .005 with a 125 machine finish was
the standard for ordering a production part that would be on a mass produced scale.

However, +/- .001 could be ordered on a higher price scale. That's close to a
press fit. The higher price would be to cover the unavoidable higher scrap percentage.

And a 125 finish is standard machine finish, but a 63 finish is very shiney with less tool marks per inch, and a 32 finish
was like chrome or glass.

Or is it the other way around. It's been 40 years. :D

It's been a very long time but you brought back some fond memories.

Ron

--- End quote ---
Very interesting thread! LOL, "higher price would be to cover the unavoidable higher scrap percentage" describes my "seat of the pants" machining using a Chinese bench top lathe and my "whittle down till it fits" machining style.........

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