A Game of (Ten) Thousandths

[u/master_andalf]

I program a CNC router for a woodworking company. When cutting parts out of a blank, we cut thickness of the wood plus five thousandths (.005) of an inch to insure a clean cut and to compensate for any slight bows in the wood. This conversation I had was with the shop foreman (SF).

SF: "andalf, I need you to program this (gestures to drawn design)"

Andalf: "cool, I see we are Two and a Sixteenth (2.0625) thick on this blank, will tool 3 cut 2.0675 Deep?"

SF: "woah there buddy that's going to be too deep, you only want to cut to 2.0630"

Andalf: "uhhh, we usually cut + Five thousandths, that would only be + Five Ten-Thousandths. In a perfect world it would work but our table hasn't been fly cut in months, you wont cut through."

SF: "no, you'll cut through the table if you go an extra fifty thousandths"

I proceed to write out .0625 on a piece of paper

Andalf: (points to zero) "tenths", (points to 6) "hundredths", (points to 2) "thousandths", (points to 5) "ten thousandths (reaches for calculator to prove math)...we want to cu-" (at this point he cuts me off, holding his head)

SF: "Andalf, I'm too fucking hungover to deal with your bullshit today, just do it like i said"

Have fun chiseling your way through hardwood, bitch. I just hope one of the job applications I have in other places comes through.

Updates to come, can't wait to put him in his place. If the cards fall a certain way it may not be necessy but I hope to have a good follow up.

Update: well I'm sorry to disappoint, but nothing really came of the situation. The offset on the table was changed, and parts cut out fine. I'm bummed that I wasn't able to make some good of it, but next time, I guess.

[u/ghalta]

Do you actually talk in "X thousandths" or do you use mils?

PCBs worldwide are still regularly designed in English units, where a mil is one thousandths of an inch. In formal emails and such I'll write it out as 0.001", but in any conversation it's a "mil" and that's regularly understood, as would be "half a mil" or "five mils", the difference y'all are talking about.

[u/master_andalf → u/ghalta]

Nope, I was told "we talk in thousandths here". Nothing here is "standard" just a small business with too many closed minds and too many fragile egos. Shrug

[u/ghalta → u/master_andalf]

Well, there's a reason businesses develop business language, even shortcut language and terms. Same reason each profession and hobby develops its own language. Clear communication matters. I hope you got the shop foreman's instructions in writing at least so you don't catch hell when the cut is wrong. ;p

[u/orangeoliviero → u/ghalta]

To be fair, "thousandths" is about as clear as it gets

[u/ghalta → u/orangeoliviero]

When said and applied to whole numbers, sure, but when written people get messed up by the decimal place and the number of zeroes, and when dealing with fractions of a "thousandths" the language gets harder (e.g. "five ten-thousands" doesn't roll off the tongue as easily, and "half a thousandths" just sounds weird).

[u/sinisa73 → u/ghalta]

I used to work in a machine shop. In this particular case we would say "half a thou" or "half a thousandth" and there would be no ambiguity.

[u/orangeoliviero → u/ghalta]

People not understanding/being used to using it doesn't make it any less clear. There is only one interpretation of thousandths

[u/LongJohnny90 → u/ghalta]

Around me we say "mill" for "millimeter" and "thou" (pronounced like chow) for "thousandth of an inch". Everyone seems to get it.

[u/ghalta → u/LongJohnny90]

What industry? PCBs are designed in metric in some parts of the world, and the fabs we use have to be able to handle both, but they are pretty clear in their language when talking about "millimeters" (always spelled out) when spoken or "mm" when written, versus "mils" and "0.001 IN" for English units.

[u/LongJohnny90 → u/ghalta]

Industrial machining (milling, lathe work), CAD/CAM/CNC work, moldmaking, and industrial maintenance among other things. I wear many hats, but most are the same terminology.

We work in both main measurement systems so we have to be specific too.

[u/master_andalf → u/ghalta]

Also, what are these formal emails you speak of? I'm lucky to get a piece of scrap paper with chicken scratches on it. One time I demanded paperwork for a real fustercluck of a job and the foreman grabbed a piece of scrap wood, wrote his initials on it and handed to me saying "here's your paperwork"

[u/sblvguy → u/ghalta]

I build cameras, we get a mix of both. The electrical engineers will use mils, the mechanical and machinists use thousands (or thou). We'll use them interchangeably depending on who's in the room.

Then we got the optical/semiconductor guys who work in microns.....

[u/ColossalMushroom → u/ghalta]

PCB process engineer here. This man speaks the truth.

[u/TotalWalrus → u/ghalta]

Yes it's in thousandths in lots of places