Almost friendly discussion lead to- Is .02 the same as.020. I say yes , he says no.:whacked: :HMMM:
Printable View
Almost friendly discussion lead to- Is .02 the same as.020. I say yes , he says no.:whacked: :HMMM:
i see both as " twenty thousandths " .. when used in a machine shop venue the amount of #`s after the # 2 is indicative of the amount of tolerance that is considered to be figured in .. hence .02 may have plus or minus 10 thousandths where .020 would have plus or minus .001 thousandths
In theory your friend is right. .02 has only two digits to the right of the decimal place, which implies that the reading is in hundredths of an inch, so it could be expressed as two one hundredths of an inch. .020 has three digits to the right of the decimal place, which implies that the dimension is in thousandths of an inch---so would be expressed as twenty thousandths of an inch. As we all know, anything measured in thousandths is ten times more accurate than something which is measured in hundredths.---It gets kinda like fighting over how many angels can dance on the head of a pin---but---theoretically--your friend is correct.
$0.10, 10 cents, or a dime.......all are valued the same, but expressed differently given the supporting context of the situation. I'm with Brian on this one.
In the machinist trade, thousandths is the language.
You could say 1/8th inch....but to a machinist, it will always be .125. You want to be understood, and to communicate what you mean, without being misunderstood, do it in the common terms.
I spent a number of years working in the trade, so I am not just debating the point.
HotRodPaint:I am like you I spent many years working in the Tool & Die Industry.Normally when you saw a two place decimal (.02) you could hold that tolerance easy,usually + or - .010.When you saw a three place(.002) decimal it was usually + or - .005 which required a little thought.When you saw a four place decimal (.0002) it was usually + or -.0001 and you were usually grinding to hold that tolerance in a controlled environment with calibrated measuring instruments. I know greater tolerances are attainable but they never came my way.
I'm in Tool & Die, I build Investment Molds, and specialized in airfoils, Turbines & turbo's. We have lost most of our tolerance yrs ago, we have to be with in .005 in one place (.1), with in .001 on two place (.12), with in .0005 on three place (.123), and with in .0003 on four place (.1234) @ 72 degs.
Years ago on a .1 Number, using a scale was almost close enough, and a dial Veneer (dial very-near) was used on .001 (I have always used a micrometer) Give 10 people a veneer and you'll have 10 different numbers.
Pat
.02 and .020 are the same measurement. Tolerance is determined by the engineers.
Maybe I am out of touch. I worked for Hyster Corp. making production parts, and obsolete replacement parts. After that I worked for a foundry, machining mining machine components. I've never even seen a drawing done in hundredths of an inch, and the tolerances were usually spelled out, or an engineer would tell me what he wanted. The most exteme tolerances I worked in were .0003
In school I was taught that .020 is two one hundreths and .020 is twenty one thousanths. They are both the exact same thing. You can say Tomato or you can say Tomatoe. Same thing.
.02 and .020 are NOT the same.
If something measures out to .02 it might be anywhere from .02 - .029
.020 is anything from .0201 to .0209
Your friend thinks it doesn't matter? Then tell him to check the prices at the gas pumps. They COULD leave it at .01 but they don't. they take it to .001 and they do it to make MORE MONEY.
.02 ends because there is only an expected 0 for infinity
.020 """ """ """ """ _______________________""""""""" etc
they are the same measure ..
when you make it .021111111111111 then it is not the same measure as
.0209999999999999...
In my GE machining history a long time ago and then my design positions - our design practices said .02 meant .020, .0200 or .02000 or for as long as you wanted to add zeros to the end. There was no tolerance implied. If there was a tolerance, it was either stated in the title box on the front of the drawing (usually another drawing, called a spec) or at the specific dimension itself if it deviated from the spec drawing allowance. It didn't mean .021, .022, .0201 or any other dim.
Many companies have design practices that deviate from this and do allow you to make assumptions - but you sure don't have that luxury on a 43 inch long staem turbine blade or 100,000 pound (plus) shaft that rotates as high as 5000 rpm or more. If you can find a copy of Machinery's Handbook, my newest is the 21st edition(old), there are about 50 pages of a chapter, Allowances and Tolerances, and another 10 of measuring instruments that are guaranteed to induce sleep.
Denny---Somebody is pulling your chain!!! Gas at the pumps in ontario is $1.05 a litre for the cheap, low test stuff. that works out to 1.05 x 3.78543=$3.97 per US gallon.:CRY: :CRY: :CRY: --Brian
Quote:
Originally Posted by Dave Severson
Dave you are right,it's just a number.The designer determines where you should be tolerance wise w/n that number.
Years ago at IBM they tried to set an example to the world .Go with the Metric System it's simpler to use.We did double tolerancing to try and sell the idea.Result- Lots of training and money wasted.Most of the Tool Makers and Machinist hated it. I don't know what system is being used in Industry,but with all the work (jobs) going off shore (primeraly China) the system of choice I think would be Metric.
Ah Yes, Denny---But right now our dollar is worth $1.02 American, so that same gas costs 1.02 x 3.97=$4.05 american. and Hey---I seen that picture you posted of your sons girlfriend (briefly). Certainly looks like the trip to Quebec would be justifiable, no matter what the gas cost!!!
Ah, yes--the good old metric system!!! When I started in engineering in 1965 everything was British Imperial---Feet, inches, and pounds. I worked along, quite happily, measuring everything in sixteenths, thirty seconds, and thousanthths of an inch. Then in about 1974, our political leaders, in a fit of uninformed idiocy, decided that Canada was going to go metric, to "secure our future in trading with European business partners". Of course, the dumb shits never stopped to realize that out major trading partner was not Europe, and really hadn't been since the fur trappers hung up their traps. It was the good old USA, and they had no intention of going metric. Then, there ensued about 10 years of absolute insanity in Canada. Nobody knew how hot or cold it was anymore (What the Hell is a Celcius???)---Nobody knew how much they were buying at the grocery store anymore (Uh, Give me 17 grams of meat please). Aeroplanes ran out of fuel, and had to make emergency landings in Aswipe, Alberta at abandoned airstrips (Well Gee, they put 500 litres of fuel in at Toronto---Ya mean thats not the same as a gallon???) Everybody in engineering nearly went crazy, learning all this new metric system. Then we found that when our engineering drawings hit the shop floor, the first thing that happened was that the shop foreman set down with his calculator and converted everything back to British Imperial---because all the readouts on all the mills, lathes, burning tables, etcetera were still calibrated in inches, and could not operate with metric measurements. After numerous machining disasters, all Canadian engineers and designers were told to use a "dual Dimensioning" system, whereby we had to put British Imperial AND metric dimensions on all machine shop drawings. Of course, this resulted in so many dimensions on shop drawings that the poor shop guys could no longer even read the damn drawings--they couldn't see the outline of the part because of all the stupid numbers on the engineering drawings. Now we have gone full circle---and the shops that build stuff for Canada and USA want everthing in inches---forget that metric stuff. The big multi national companies lke Volkswagen, Honda, etcetera want their stuff in Metric---None of that Inch crap. Damn, I shoulda been a hair stylist!!!Quote:
Originally Posted by Don Dalton
NHRA uses the same 2 digit logic when they post reaction times and ETs. .02 is 2 thousandths of a second.
Reaction time is measured in thousnths of a second, but I believe 0.02 is 20 thousanths, not 2.Quote:
Originally Posted by Twitch
.02 = 20/1000
.002 = 2/1000
Kitz
Damn---I have to get another contract!!! This internet posting is like self abuse---takes up time and feels good but doesn't accomplish much.
Quote:
Originally Posted by brianrupnow
Brian,what I like most about this forum (minus tech talk)is it starts out on a subject and ends up totally unrelated to the original subject.You really learn a lot about everyone when this happens,I LOVE IT=======.
Don--I,m just killing time. Generally, I have a design engineering contract on the go, and that pretty well sucks up my entire day. I "tune in" 2 or 3 times a day to see what everyone is posting about, but mainly, I lurk. Last week I finished a contract job for Toyota, and this week I've sent out about 60 emails soliciting new work, but untill something comes alive, I kill time on the forums. I putter around on here, and over on the HAMB, and a bit on Streetrodding.com Sometimes I can give good advice, sometimes I just have a funny story to pass on, but mainly, its killing time waiting for that damn phone to ring and somebody ask "Do you have any experience designing____ "
if so, what are your rates, how busy are you, can you come see us tomorrow---Yada Yada Yada.
Okay---I feel better now. Wifey and I and daughter went out for dinner tonight--When I got home there was a phone message for me---a 200 hour contract to be finished early in Jan., with possibility of another 800 hours starting in mid January.--That should finish out this year in style, and get one heck of a start on 2008.
Congrats Brian: What design software are you using? We used AutoCad level 12 or 20(been a while) back in 97.
WOW, we've covered tolerances, contracts, gas prices both here and there, someones love life, a small funny and probably something I missed. Still no consensus as to whether or not .02 and .020 are the same thing. The issue has been settled though. I out drank him 3-2 and he conceded.
Merry Christmas, Guy and Dolls an a Happy New Year: 3dSMILE:
Don---I made the transition to 3D solids about 7 years ago. I now work exclusively in Solidworks. I worked on a drafting board for 32 years, then at age 50, due to increasing customer demand for computerized drawings I went back to college and learned Autocad 2D. I learned on version 13 (horrible) then moved up to version 14 (great). After 3 years working in 2D autocad, customer demand forced me to make the transition to 3D solid modelling. I now do all my design in 3D, and teach 3D solid modelling to other engineering and design companies.---Brian
www.rupnowdesign.com
[Give 10 people a veneer and you'll have 10 different numbers.
My experience has been, give ten people a verneer caliper and they will make a career out of trying to figure out the dimension, never get it right and say that is allowable tolerance.:) I do know an elderly gentleman who can read a verneer as accuratly as a mic. Says his first lathe was ran by a foot treadle till he got a steam engine to run it.