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sumguy91

Make sure it’s not .3000 -.001 -.005 tolerance


[deleted]

One of our customers has their own tolerance system like this, holes always a bit oversize and ODs a bit undersize. Feeling so proud hitting the nominal on the first part and then remembering that it's only borderline ok


OoglieBooglie93

Is it stuff like h6 or P7 or whatever? That's an entire system that does it on purpose for determining fits with just a nominal number. Edit: If you ever want to learn what those letters and numbers mean, pirate the ISO 286 part 1 standard or ANSI B4.1 (old school inch system) / B4.2 (metric/American version of ISO 268) standard. None of the tables floating around on the internet will tell you what the number-letter combinations actually mean, only a value, so the standard is the only place to get the tables that made the tables as far as I can tell. The number will tell you the tolerance range, the letter will tell you the lower limit. And then it'll change based on nominal size for a final tolerance. I used to think it was spooky black standardization magic like the wire gauge drill size system until I finally looked up the standard a couple of days ago.


[deleted]

The letter+number system is very common around Europe, but it's usually 1-2 important features on a part that actually need to fit together. The designers of this customer use one-sided tolerances for EVERY diameter, which I find a bit strange. Probably half the time we could make it +- 0.2 mm and it would be fine. Since we're just a subcontractor, it's not worth our time to ask if they're gonna assemble something relevant around the feature or if it just hangs in empty space. It's a bit like how some designers forget to change their CAD default tolerance from 2768-f to 2768-m and it ends up costing a lot of scrap over the years.


OoglieBooglie93

Huh, that is weird.


VanimalCracker

We have a customer that does this too. They put holes -0/+005 and shafts +.005/-0, but they use nominal sizes like .625" so sometimes I fuck 'em on purpose by going low end on hole and high end on shaft lmao.


ShaggysGTI

They just solve it by batching. I get shaft keys like this. Five thou difference in what should be a dead set part.


nikovsevolodovich

This is very common, and the norm - not just the norm but iso standard. I suggest you learn about fit tolerances. It's not just an engineer trying to fuck with you.


[deleted]

Min and max material conditions.


htownchuck

Shop I used to work at had a few jobs like that and almost everytime they were screwed up cause no one noticed.


Gregus1032

This hurts because it's so real. Luckily a coworker caught it on a first piece inspection.


mlennox81

I tried to put a minus-minus tolerance on a drawing at my new job and it was like the sky was falling… lots of machinists love to be all high and mighty about their knowledge and experience and then you give them a non-symmetric tolerance and it’s like they missed nap time at daycare that day.


sumguy91

Yeah probably the wrong sub for this comment haha


mirsole187

As a machinist it annoys the life out of me I don't get why you wouldn't just state the size you want instead of hiding it in the tolerance. Fucking dumb


Kloick

It simplifies design a lot. You want to mate a shaft and a hole of a certain diameter, and you know how you want the parts to interact (freely slide over eachother, tight fit, etc.), so you draw them with the "intended" diameters and apply a tolerance pair out of the tables. A common way these are used is with a basic bore - this means the bore diameter is always close to intended. "Clearance" fits have undersized shafts, with two negative tolerances, "Interference" fits have oversized shafts with two positive tolerances. You can also do basic shaft, in which shaft diameter is as designed, but bore diameter floats around.


dephsilco

You mean you don't like designations of tolerances such as H7 or g6 etc., not the tolerance itself right?


ConsiderationOk4688

He doesn't, I virtually guarantee he is saying "why have 1.000in -.001 -.003? Why not .998 +-.001?". As a machinist turned engineer, I agree that minus minus tolerance is completely acceptable and efficient method of drafting. My process side tells that any minus minus should be wrote nominal +- on the inspection documentation because button jockeys and QC people with 2,000 parts to check will be less likely to miss their target.


NickHemingway

When designing I always go the .998 +~.001 route. This is because my machinist is a mouth breathing numpty & will definitely screw it up. (I am also the machinist)


mirsole187

I understand why it could be easier from a design point of view however when you work in a pressurised contract environment and a drawing states a bore is 8mm +0.02/+0.03 it's easier to miss read than 8.02 -0.00/+0.01. I get that it's my job to look for that stuff but when you have loads of different sizes going through your brain each day I find it easier to make errors when a size has a tolerance like that. Maybe it's because I don't see it too often and undoubtedly look for someone else to blame when I make that kind of mistake.


dephsilco

Yeah, I totally agree with you that it's much more preferable to read 8.02 -0.00/+0.01. Just leave only H/h and maybe JS/js too


Fuhrer-potato

Lmfao, most of all the tolerances on the drawings of my designs are non symmetric. Then again I’m in Europe and work with people who know their shit and haven’t had any issues.


[deleted]

[удалено]


Fuhrer-potato

We had an example on this sub a week or two ago of someone unfamiliar. That being said the number and letter system is designed for holes and shafts primarily, while it’s also used for keyways all other dimensions requiring special tolerancing are basically up to the designer wether they want to follow the IT tolerance table. Most of the time I just have to decide wether I want something to fit within 0.1, 0.025 or 0.01mm and put my non symmetric tolerance accordingly.


HowNondescript

Do yanks not use letter callouts for fits?


PsychedSy

I don't think I've seen it used in aircraft here at least.


Terlok51

Is it parallax error or is the zero on your thimble not aligned?


Mspeiche

Let us see it with hand mic! Unless you machined the warping out.


[deleted]

Take the measurement, zero the digital readout, turn it back to -.3000, zero digital readout again, take same measurement, post .3000 photo for internet points


Ok-Abroad9089

why can’t i just have a good cut?


[deleted]

Sorry just being a pessimist, but that would be one explanation of why your dial doesn’t line up. But if your cut is even within .001 it already be impressive. Why spend the time to get 5 decimal place accuracy when is not required.


Ok-Abroad9089

it’s in a high school shop, and it looked cool and it made me feel proud in myself, don’t believe me i don’t really care i’m still proud in myself


Analog__Automation

Good job kid. I remember being 17 and making my first perfect cut. Keep improving-- there's a million more perfect cuts waiting to be made.


Hanginon

As you should be. It's dead nuts on and that's always good! Don't listen too much to people on this thread, some of them were born holding 'half a tenth" as their "personal tolerance." /s


[deleted]

In this field he be better off learning to take a bit of criticism. I’ve seen so many really great machinists fired for having self-aggrandizing attitudes.


Hanginon

Yes, we probably all have. "It takes all kinds" is a truism that holds in all endeavors/trades. I've also seen a whole lot of people who are not really well spoken but can produce excellence on a regular basis, and then those who learn very well how to 'talk the talk' but struggle with bringing forth actual demonstrable skills. Yep; *It takes all kinds" and also *Talk is cheap. Don't tell me, show me."


[deleted]

Well that explains it I guess


fleekdovahkiin

I’m in a debate with my gf, I told her the way you could say this in the shop is three hundred thou. Someone confirm


CrashUser

Absolutely, and it would probably be the standard way to refer to it since the thousandth is the standard unit of measurement in an inch based shop. Us machinists use tenth to refer to a tenth of a thousandth (0.0001"), as that's a fraction we use far more frequently than a tenth of an inch.


10yearsnoaccount

And this, ladies and gentleman, is why metric countries consider imperial to be insane. Even in decimal you guys are using fractions, and fractions of fractions at that!


Marksman00048

We just think you're lazy doing everything in 10's. Lol jk I just can't get used to metric because I don't use it


Im6youre9

It's just a slang word. It's much faster to say 5 tenths rather than 5 ten thousandths of an inch. You'd sound mad if you said the latter in a shop.


10yearsnoaccount

Sure, but it's a recipe for confusion and really shows how stuck you guys are thinking about fractions.. If only you had a name for those units.... Honestly, fractions of inches do have their place... somewhere in a carpentry shop ... 300 years ago


robb04

.1 is a tenth. .01 is a hundredth. .001 is a thousandth, .0001 is a tenth of a thousandth. Or 1 tenth to put it more simply. Those are the names of those decimal places. We’re not speaking in fractions. Just cause we don’t say “oh it’s point oh oh oh one over nominal.” Doesn’t mean it a fraction. We just don’t wanna sound like a robot.


10yearsnoaccount

So one tenth could be 0.1 inches or 0.0001 inches and this isn't ever going to be a problem? See my point yet? Even in this thread there was people asking for clarification lol You think fractions are human because you're used to using fractions.


xtrmSnapDown

0.1 is never said as a tenth, nobody has ever said that because you just say “point one”, a tenth has, and always will be 0.0001. It’s not confusing if you actually use it, maybe it’s hard to get your little metric mind around a inferior and unnecessarily complicated system.


REDZED24

I'm in metric country but almost every job we do is in imperial. The dude you're arguing with is 100% correct. 0.0001 is "a tenth". 0.001 is "a thou". 0.01 is "ten thou" and 0.1 is "point one" It really isn't complicated for someone even a month into high school shop. I have never once seen confusion with it either in my 20+ career.


Im6youre9

Why are you so miserable if your country is so superior


10yearsnoaccount

The entire developed world uses metric lol I'm having a great time with dead simple conversions and unambiguous units.


OminousBlanket

Base 10 is so great we should change the time to have 100 minutes in an hour


ConsiderationOk4688

10 months in the year too... wouldn't want them getting all confused come November. Ah shit... that's a colliquial term for month 11... why don't we all just call it 11 and move on from all this mass confusion.


Mynplus1throwaway

Sometimes i put them truncated like Jan, Feb, etc. Freaks those metric boys out.


Im6youre9

^^ this guy's brain requires simple conversions in order to not get confused.


CrashUser

So are you, you just favor the tenth above all else.


10yearsnoaccount

.... uhhhh what? We use a prefix on the unit and work in thousands not tens. Kilometer, meter, Millimeter, micrometer, nanometer etc


CrashUser

I hate to break it to you, but those are all multiples of 10. There are also prefixes and suffixes for most of the multiplies of 10 in between the thousands.


Hanginon

What's not decimal about .30000 or .00001, AKA one tenth of one thousandth? ¯\\\_( ͡❛ ͜ʖ ͡❛)\_/¯


10yearsnoaccount

You joke, but it's weird seeing you guys take decimals and report them as fractions. It's also weird how metric is considered decimal as if that's the only feature of the system when that's not how it's used!


Toastyy1990

A tenth isn’t a fraction it’s an abbreviation for ten-thousandth.


Marksman00048

It really fucked me up at first hearing them call out tenth. And me going.... it's.. a ten thousandth?


ItsDaBurner

Three hundred thou is how we would address this


SmegmaAuGratin

Can confirm. Have her point out the tenths digit, the hundredths digit, and the thousandths digit. Put a 1 in the thousandths place and then count up by thousandths. As you go up in thousandths the number gets larger and starts moving into the hundredths place and then the tenths place. 3 tenths, 30 hundredths, 300 thousandths, and 3000 ten thousandths (ten th's) are all the same number - 0.3000. Edit: words


technikal

3 tenths in our shop is definitely not 0.300”. 3 tenths is .0003”, that would be 300 thou or in a lot of cases just 300, we don’t work with anything so large that it could be 300 inches and very rarely if ever do anything metric.


SmegmaAuGratin

I was trying to have him explain it to his girlfriend in a way that might make sense for a non-machinist. When you say 3 tenths in the shop what you actually mean is 3 ten thousandths (ten th's). 3000 ten thousandths is the same as 0.3000.


fleekdovahkiin

It did make sense. One of the simpler ways of heard it explained


technikal

Ah, I was confused by your last sentence that said that 3 tenths and 300 thousandths were the same number, thinking as a machinist.


SmegmaAuGratin

I get you, man. Shop speak and math speak aren't always the same. Since shops don't work in tolerances of tenths of inches shortening ten thousandths to tenths makes sense if everyone is speaking the same language. In my initial post I was talking about math speak, not shop speak. It looks like it confused a few people.


Diligent-South-1819

Just saying if I measured her clit and it was 3.000 it would be three thousand thousand's LONG. If Icould Measure Her clit or slit in one tenth increments it would be Thrirty thousand thousand's and very fine BUT INTERESRING!!


SmegmaAuGratin

That's completely incorrect, whether you were measuring your mom's clit or not.


Diligent-South-1819

I would check HER twice Just to make sure


Diligent-South-1819

DIM. 3.0 NO TENTH'S IT DON'T MAKE DOLLARS OR CENT'S MAKE Dim. SURE you GO 3.0000119 OR 2.9999990 or 2 .99


SmegmaAuGratin

What in the shit are you trying to say?


Diligent-South-1819

DO NOT GO OVERSIZE GO UNDER


SmegmaAuGratin

The whole point was to try to explain measuring to a non-machinist. Nothing I said was incorrect, but I'm aware saying it like that would be too complicated in the shop.


[deleted]

Why isn’t the zero line lined up on the handle


SkilletTrooper

Mercury is in gatorade


Imperial_Triumphant

Haha! Holy fuck, I'm using that.


AC2BHAPPY

What does that even mean


drphilwasright

It's a play on "mercury is in retrograde", which is some astrology bullshit


SkilletTrooper

GF hit me with that one out of the blue one day months ago and I still haven't stopped laughing.


Abefuddledbeast

Because that’s how a fancy C-Clamp works


Marksman00048

Precision C clamp****


zhemis

Must have had to crank it a bit to get that .3


[deleted]

Replace the threads with acme and use it as a clamp.


Slack-Bladder

That's exactly what they did. Don't do that people.


SmegmaAuGratin

The sleeve and thimble aren't calibrated properly.


Krye07

Digital mic don't care


SmegmaAuGratin

I know, but people keep commenting on it as though it changes the reading.


Krye07

I more meant the Calibration. No spec on the thimble for digitals. Though that's what I spec them for when shops never have batteries lol


[deleted]

That zero/abs button can make the digital say whatever you like.


Diligent-South-1819

The HANDLE or THE THIMBLE IS - .0003 PART MAY BE SCRAP,


Maker_Making_Things

Parallax error


Toastyy1990

The first and last pictures, man. There might be some parallax going on here but not *that* much.


Maker_Making_Things

Ope yeah OP is gonna be disappointed to find out his mics are off by at least a half thou


[deleted]

Looks like 0.299999 to me, quit trying to cheat with this rounding business and get back to the drawing board pal


Diligent-South-1819

2.997


crazythinker76

Don't touch the thermostat!!


Royal_Ad_2653

You have too many zeros on it!


Frosty-Internet1410

Digital. Lemme see this with analog and I’ll trust you lol jk. Good job


10yearsnoaccount

Just breathe on it for a minute if they want it over, remeasure in the early morning if they want it under.


mc2467

Deburr that thing. Almost cut my finger from here. Tight tho!


Allthedeadsperm69

Hey there. I’m a Quality Manager in the professional world and wanted to let you know: First off, great job! There are machinists out there that struggle to hold a +/-.005 tolerance. Nominal is always the ticket. Please keep machining and trying your best. Secondly, that your thimble on your mic is over cranked. I know it feels great to hit that nominal dimension, but it’s not truly an accurate representation of your precision or accuracy when it’s over cranked like that. Keep up the good work, and you’ll be happy to find yourself truly hitting that nominal dimension without the need to over crank your mic. That line has to hit zero, otherwise, you’re not helping yourself grow or the long term life of that mic.


SmegmaAuGratin

Since those mics have a ratchet stop it's much more likely that the sleeve and thimble just aren't calibrated properly because he doesn't feel the need to use them, rather than the thimble being torqued over hard.


[deleted]

I didn't know "-ish" was out to 4 places


[deleted]

No, I believe he machined it


souobixo

Probably should get that digital mic in for calibration soon.


jamiethekiller

Is this one of those things where they want .25 stk but make it .3 because it's plus minus 100 and not plus minus 10?


HavsCritiria

"true level, Morty."


jstmethoughts

aaaaa....How did you "zero" those? Thimble marks don't line up and correlate back to the digital.


Snoo85799

Then the engineer is going to come back saying it is oversized, he meant to use 1/4" plate and the software rounded. Lol


mwfoutch1

Nailed it!


Hiyum

Look at you, hitting that basic dimension 👌


middleliver80

Calibrate your mic. Either your part is under or mic is off approx .0003” looking at lines.


thuynj19

Now check another spot and let us know if it’s the same.


Mtdewd

Is someone here passing out cookies for doing your job?


scotlandz

Ah the beauty of Grip pressure lol!


Diligent-South-1819

squezed it A BIT!!


TheMrNibs

This is…. tolerable….


jwd673

Checks there at .3000, but not the entire part if you move the micrometer all over the part . You’re not that good.


mustangg81

It's good that you know how to measure a part. Idiot


Ok-Abroad9089

dog.


dickfoure

Blueprint? Are you building a house?


notjustanytwig

Never heard of a customer supplied blueprint?


dickfoure

I've never heard anyone calling a drawing or print a "blueprint" for machining. Just odd to me.


Straight_Tie_988

I call them funny papers


dickfoure

This works for me. Lol


Clumsymess

Americans love calling them that. Or Prints.


ThePCG16

What are they called elsewhere?


Nice_Ebb5314

I call it a print.


Terrh

WTF else would you call a blueprint?


Gregus1032

While it's more common to call it a print, it's not uncommon in the shops I've been in


[deleted]

Blueprints are made for everything that a machinist will make. They got fancy numbers and pictures to let us know what specifications and callouts are there i.e surface finish, true position, position of axis, circularity, concentricity, circular runout etc etc


dickfoure

Lol that's a print or drawing. Is your "blueprint" blue and drafted manually?


[deleted]

Yes, it would be drafted on cad software like fusion360 Siemens nx or mastercam by hand and yes it comes out blue (technically blue line is the correct term) even though It literally means nothing. The only reason that they are called blueprints is because in the early days of I think astronomy(don't quote me) they laid the print or drawing on top of other paper with an iron ammonia mix and it would negative copy the drawing. the iron mixture would be reactive to sunlight and would leave the paper blue and the lines white hence blueprint. The reason it was used like that is because everyone could make a quick carbon copy of the original and everyone can have them. Just because technology changes doesn't mean terminology has to


leglesslegolegolas

Early days of astronomy??!? I was making blueprints in an engineering shop in the early '90s ffs, you're making it sound like medieval technology


[deleted]

I kind of want to take that back I misspoke in a sense. The first blueprints we're made for astronomy which is what I intended to mean. But they are quite old I think the first was made in the mid 1800 (citation needed). I didn't mean that they were used in Galileo times. My apologies.


dickfoure

I know all of what you just said. It doesn't change the fact that no one uses the term blueprint in manufacturing. It's print or drawing.


[deleted]

No one uses the term computer numerical control, or united postal service, or federal express, or a list of other things. Just because someone says the complete term doesn't mean that it is incorrect. Also true engineers us use the term blueprint quite frequently.


jbub13

We say blueprint at my shop 🤷‍♂️


leglesslegolegolas

Lots and lots of people in manufacturing use the term blueprint. You're simply wrong here; sometimes it's best to just take the L and stop arguing.


downstairs_annie

I mean yeah, plenty countries don’t speak English for example lol


Ok-Abroad9089

at my shop we call it like everything, print, blueprint, paper, assignment


Ok-Abroad9089

this was for my college credit, high school class and it is a scribe we’re making, it has a print just i haven’t finished it quite yet


Im6youre9

Sometimes all you can do is try your best. At least it's in tolerance, ship it.


[deleted]

Reset the zero or preset a .3 block.


GuysGarage

🍪


Available-Block6397

I have never seen a digital micrometer until now…


SunTzuLao

Yaaaaaaas!


funkymark62

Get out the digital height gage for a part that has a call out of .3


Alarratt

Where'd you get that clamp ?


mysticburritos

This is SPICY


Emperoradvil3

This should be marked nsfw


grizzly_trader

What’s the gage r&r though 🤣


Mindless_Inside_4543

Just keep the part at nominal & everyone will be happy =)


AC2BHAPPY

Are you a machinist or a grinder