View Full Version : Math needed for welding

Beagle Fab

01-16-2009, 09:49 PM

I am currently taking some welding courses, but it moved straight into more hands on training as opposed to classroom getting used to measurements, welding symbols, blue prints, exc. Coincidently, I am also taking a some advanced math courses to shore up those skills.

Any recommendations on the type of math I should gear up on? Trig, Geometry?

Magnetic Mechanic

01-17-2009, 12:03 AM

If yer gonna do any layout, you gots ta have geometry.

lugweld

01-17-2009, 12:16 AM

Geometry definitely, particularly if you do fabricating. But trig, is helpful, though I can't hardly remember a thing about it. Accounting math might be nice....got to keep those books.

Static-XJ

01-17-2009, 03:00 AM

Trig. Very useful, sine cosine tangent and the like. Algebra as a pre-req, it's a foundation for solving all sorts of stuff.

If you work in the US, knowing how to convert from imperial to metric measurements can be handy, and likely will only become more so with time. Being able to apply the correct conversion with the correct math.

Being able to take degrees and convert that into length measurements on an arc. For example a part that is essentially a large arch (30' length of a circle with radius of 150') had brackets spaces every 7.9°, had to be able to use that information to mark locations for the brackets.

Being able to estimate volume, and convert volume into weight. Very useful if you're dealing with larger items and overhead lifting.

I would also recommend knowing how to do math long hand, without a calculator. Including long division. Sometimes it's more convent to just write the math out than it is to go get a calculator.

As for weld symbols, I'm assuming that you're located int he US and are learning ANSI/AWS weld symbols. I would try and at least take a look at some ISO weld symbols as well. They are similar, but have differences. Particularly in arrow side vs other side designation, weld dimensions, and intermittent weld lengths/pitch. Be familiar enough that you can recognize which a symbol is, and be able to look up how the welds are called out.

mn welder

01-28-2009, 02:59 PM

definatly geometry and when iwas in school at ndscs we had a practical welders math book that was the thing also fractions, decimals and a very good calculator where you just plug in formula and get your answer

A_DAB_will_do

01-28-2009, 05:28 PM

Start with sound fundementals...some of the guys I attended welding school with couldn't add, subtract, multiple, and divide; even with a calculator. Know how to perform all these mathmatical operations with fractions and decimals. Be comfortable converting from fractions to decimals and back. Someone else mentioned the metric system. I second this suggestion. Understand how to convert from one unit of measurement to the other.

If you've mastered all this already, then look at geometry. A few simple concepts, like a 3,4,5 right triangle will enable you to build things square. If you don't know, ask someone to show you the proper technique for using a tape measure, plumb bob, and spirit level. Knowing how to use these tools properly will help you avoid a lot of time consuming mistakes.

Best way to learn how to read blueprints is to learn how to produce one yourself. Take a drafting course if you have the time. There are lots of good reference books on welding symbology that can provide the details you're looking for.

I am currently taking some welding courses, but it moved straight into more hands on training as opposed to classroom getting used to measurements, welding symbols, blue prints, exc. Coincidently, I am also taking a some advanced math courses to shore up those skills.

Any recommendations on the type of math I should gear up on? Trig, Geometry?

Beagle Fab

01-28-2009, 09:57 PM

Thanks for all the suggestions and recommendations! I've got the fraction/Dec conversions down cold, and all the adding stuff well in hand as well.

That said, I really like the Drafting course/study idea and that is a great suggestion! Welding symbols and blueprints as well!

Thanks again!

Fat Bastard

01-28-2009, 10:18 PM

I am currently taking some welding courses, but it moved straight into more hands on training as opposed to classroom getting used to measurements, welding symbols, blue prints, exc. Coincidently, I am also taking a some advanced math courses to shore up those skills.

Any recommendations on the type of math I should gear up on? Trig, Geometry?

I find that I use all 4 types of math addin miniusin timesin and dvidin

anything else?

steve45

01-28-2009, 10:44 PM

Look at this and see if you can figure out how to lay it out: http://weldingweb.com/showthread.php?p=247091#post247091

That will give you an idea of what you might need to know.

get a copy of "MATH TO BULD ON" its about $25 a great reference when you need to look up the right formula isbn # 0-9624197-1-0

Donald Branscom

03-05-2009, 02:37 AM

Simple geometry - like if you have a round steel disk how do you find the center?

Figuring supplies for a job. But there is a hand held calculator made just for welders that can really help you with this task and i have seen it in Welding Journal magazine.

Weights of materials - like you are going to load a 1 ton truck with steel plates and you want a safe load.1/4 inch steel plate weighs 10.2 pounds per sq.foot.What would a safe load be?

Weights of materials are very important.

How large of a tank to hold 10 gallons of liquid. Etc.,.

dr stan

03-14-2009, 12:33 PM

All of the previously posted suggestions are excellent, especially those referring to trig, geometry, and drafting. I would however add a couple of thoughts. If you can find a board drafting class instead of AutoCADD it will serve you better. Unless you are using a CNC cutter you will be doing your layout and cutting by hand. Thus the skills you learn on the board are directly transferable to sheet and plate stock. If you can take a class in Descriptive Geometry that is taught on the board that will improve your math skills in ways that will serve you best.

Another source of info is the Audel’s series of technical books. Don’t just concentrate on the welding books, but also look at the millwrights, carpenters, and other tradesman books that contain math information.

Glad to see someone pursuing your craft with such a focus.

smc1118

12-30-2016, 01:26 PM

I need help I need to learn math fast and for free because I don't have the founds to go back to school for it but I was always bad at math really bad and I am realizing that all the good jobs you need to know math can any help me or point me in the direction of some really good websites thank you all

Sent from my XT1585 using Tapatalk

WNY_TomB

12-30-2016, 02:30 PM

I am currently taking some welding courses, but it moved straight into more hands on training as opposed to classroom getting used to measurements, welding symbols, blue prints, exc. Coincidently, I am also taking a some advanced math courses to shore up those skills.

Any recommendations on the type of math I should gear up on? Trig, Geometry?

.

same old horse, caught another horse, taking oats away

Sin=opp/Hypotenuse

Cosine=Adjacent / Hypotenuse

Tangent = Opp/ Adjacent

also A squared + B squared = C squared

.

most places you cannot get the job if you cannot do basic trig. making stairs and other jobs it can be useful.

docwelder

12-30-2016, 02:41 PM

having nothing but the basic math fundamentals i would recommend the new guys learn all they can. once you get a little older it's very difficult to absorb.

b-dog

12-30-2016, 02:54 PM

I need help I need to learn math fast and for free because I don't have the founds to go back to school for it but I was always bad at math really bad and I am realizing that all the good jobs you need to know math can any help me or point me in the direction of some really good websites thank you all

Sent from my XT1585 using Tapatalk

Geometry is probably where you want to start. I imagine 5 minutes Googling/reading would provide plenty of questions that you can then research further. Rinse, lather and repeat. Check the library for books. Books will probably be easier to learn from than the internet.

Depending on your situation, look for some grants & scholarships. I don't think I would be able to teach myself a big general subject like math, it's just too overwhelming but maybe you can. Add an English 101 class in there too. Not being an *** on purpose; I graduated high school with poor English writing skills. English 101 was worth the time and money.

WNY_TomB

12-30-2016, 02:58 PM

having nothing but the basic math fundamentals i would recommend the new guys learn all they can. once you get a little older it's very difficult to absorb.

.

.

my preference is to draw it in Librecad and then pick points and it says what dimensions are and i can print it out

.

it is available as a portable app which runs from usb flash drive, no need to install anything

.

http://portableapps.com/

.

nothing wrong with doing math but double check math. embarrassing to make math mistakes worst ones are

.

confusing 1" 1" with 11"

.

doing big stuff and so busy measuring 1/16" that was off exactly 1 foot measuring opposite corners.

It looks like using math this could be 7 years old , 2009 and now 2016 :dizzy:

jrporter

12-30-2016, 03:10 PM

There are lots of online resources - just do a search for learning math and you will get a bunch of hits. Just don't let anybody sell you anything you don't want to buy. math.com looks like an OK place to start, but there are many places you can go to that have tutorials etc.

docwelder

12-30-2016, 04:28 PM

.

.

my preference is to draw it in Librecad and then pick points and it says what dimensions are and i can print it out

.

it is available as a portable app which runs from usb flash drive, no need to install anything

.

http://portableapps.com/

.

nothing wrong with doing math but double check math. embarrassing to make math mistakes worst ones are

.

confusing 1" 1" with 11"

.

doing big stuff and so busy measuring 1/16" that was off exactly 1 foot measuring opposite corners.

that's too true. one of the critical things about the fabrication trade is double checking dimensions during the build process. many times i've misread/miscalculated my measurements by one foot or one inch. better to catch it early then after it's out the door. i find my crs especially troublesome between my bench and the saw:cry:

WNY_TomB

12-30-2016, 05:05 PM

that's too true. one of the critical things about the fabrication trade is double checking dimensions during the build process. many times i've misread/miscalculated my measurements by one foot or one inch. better to catch it early then after it's out the door. i find my crs especially troublesome between my bench and the saw:cry:

.

.

always read tape measure just inches like 121" and then feet inches 10' 1"

.

laying concrete block for garage foundation and had somebody helping hold tape measure. i was so proud i had it within 1/8" over like 30 feet. unfortunately i later found out i was exactly 1 foot off. it made everything harder including cutting plywood for roof even after getting the top of walls down to within 4" of square measuring opposite corners, like each piece of plywood had to cut 1" triangle off

.

one of those things once you do it, you always remember for rest of your life. double check math, double check reading tape measure in particular feet AND inch errors

docwelder

12-30-2016, 05:12 PM

.

.

always read tape measure just inches like 121" and then feet inches 10' 1"

.

laying concrete block for garage foundation and had somebody helping hold tape measure. i was so proud i had it within 1/8" over like 30 feet. unfortunately i later found out i was exactly 1 foot off. it made everything harder including cutting plywood for roof even after getting the top of walls down to within 4" of square measuring opposite corners, like each piece of plywood had to cut 1" triangle off

.

one of those things once you do it, you always remember for rest of your life. double check math, double check reading tape measure in particular feet AND inch errors

yikes! you're not likely to forget that in a quick hurry:nono:

John T

12-30-2016, 06:44 PM

one of the critical things about the fabrication trade is double checking dimensions during the build process. :

Is that why it takes me forever to get anything done?

LoL !

I have gotten many compliments on some of the things I have built in my spare time.

And people will say why don't you do this for a living?

I just laugh and roll my eyes

Sent from my iPhone using Tapatalk

Oscar

12-30-2016, 08:28 PM

Simple geometry - like if you have a round steel disk how do you find the center

Duh, that's easy you balance it on the tip of a nail. But only if it is of uniform density throughout. :)

Blwaz23

01-02-2017, 06:15 AM

If I wanted to learn the math for pipe fitting what would be a good source to read or what books would be the best to read?

ManoKai

01-02-2017, 08:13 AM

I need help I need to learn math fast and for free because I don't have the founds to go back to school for it but I was always bad at math really bad and I am realizing that all the good jobs you need to know math can any help me or point me in the direction of some really good websites thank you all.

Recommend you watch, learn, and complete the exercises for Early Math, Arithmetic, Geometry, and Trigonometry available online from the Khan Academy (www.khanacademy.org). Complete the above Math Subjects in the order listed. If you already know a given subtopic, after checking out the content, press forward.

Starting with Geometry is not the best course of action, IMPO, until you are comfortable with addition/ subtraction/ multiplication/ &division for both decimals and fractions. Learning to effectively operate a tape measure and other layout tools, first requires a solid working knowledge of decimals and fractions.

As a former volunteer tutor in Math/Algebra, can tell you first hand that Khan Academy + your level of effort/dedication into the "journey" will yield positive results for you. You must invest the time and step through the saturation ~ incubation ~ illumination phases to truely master most challenges in life.

Good luck.

MinnesotaDave

01-02-2017, 11:03 AM

Recommend you watch, learn, and complete the exercises for Early Math, Arithmetic, Geometry, and Trigonometry available online from the Khan Academy (www.khanacademy.org). Complete the above Math Subjects in the order listed. If you already know a given subtopic, after checking out the content, press forward.

Starting with Geometry is not the best course of action, IMPO, until you are comfortable with addition/ subtraction/ multiplication/ &division for both decimals and fractions. Learning to effectively operate a tape measure and other layout tools, first requires a solid working knowledge of decimals and fractions.

As a former volunteer tutor in Math/Algebra, can tell you first hand that Khan Academy + your level of effort/dedication into the "journey" will yield positive results for you. You must invest the time and step through the saturation ~ incubation ~ illumination phases to truely master most challenges in life.

Good luck.

+1

Kahn academy is a good way to improve basic skills.

It will not give you practice in creative, career oriented, problem solving - but is a great skill builder.

If I wanted to learn the math for pipe fitting what would be a good source to read or what books would be the best to read?

These are good books to have. Also one of these calculators.

LMH Steel

07-11-2018, 10:43 PM

I keep that calculator on my phone. $20 for the app vs $100 something for the calculator. I use it nearly everyday too. I also use Sketchup to draw and they have a free version.

docwelder

07-13-2018, 10:14 AM

having modern computer,phone and calculator i would forget learning anything except the very basics of math and concentrate on perfecting welding skill.

having modern computer,phone and calculator i would forget learning anything except the very basics of math and concentrate on perfecting welding skill.

Doing the math in your head will keep your brain alive. All this modern sh*t is handy sometimes, but when the battery is dead it's useless.

My brain always works. If it stops working then nothing matters anymore.

Eric

akpolaris

07-14-2018, 04:55 AM

Basic math skill such as addition, subtraction, multiplication tables and division are essential. Knowledge of algebra & geometry are essential as well. If you can't do it on your head you need to be able to do it in writing

CrookedRoads

07-14-2018, 09:52 AM

I learned geometry in 5 grade, learn to read blueprints so you can do layout work, it can make the difference between you being the guy that's down in the hole breathing shiit all day or the guy up on the deck working in fresh air.

https://youtu.be/RitDpwVpNVQ

https://www.proconstructionguide.com/how-to-read-plans-and-blueprints/

smithdoor

07-14-2018, 10:13 AM

I am currently taking some welding courses, but it moved straight into more hands on training as opposed to classroom getting used to measurements, welding symbols, blue prints, exc. Coincidently, I am also taking a some advanced math courses to shore up those skills.

Any recommendations on the type of math I should gear up on? Trig, Geometry?You never know if you

But having training will give a egde over

Others

I found in welding old school drafting is great plus in the shop.

Good luck

Dave

Sent from my SAMSUNG-SM-J320A using Tapatalk

grizzzly

08-04-2018, 11:42 PM

in my opinion the most important thing you can do it learn the basics.

addition/ subtraction/ multiplication/ &division for both decimals and fractions. and know how to use a tape measure. everything beyond that is just tricks.

some of the best fitters i have been around only had a 3rd grade education

i am not talking calculator you have to have that **** in your head and have it good, it will make your life a lot easier and make you money

N2 Welding

08-05-2018, 12:35 AM

I so wish I had the ability to retain knowledge as most normals do. I forget more crap and have to continually relearn crap to get things done. Shoot in High school I had a hard time with Algebra and Geometry but more so with Algebra and having to write everything out by hand and do all the math took forever for the slow processor in my cranium. I hated it. Still do, get head aches from thinking to much at times.

Ok enough sniffling, there are so many great suggestions and information in this thread.

docwelder

08-05-2018, 09:15 AM

Doing the math in your head will keep your brain alive. All this modern sh*t is handy sometimes, but when the battery is dead it's useless.

My brain always works. If it stops working then nothing matters anymore.

Eric

eric; you can have the math. i'm keeping the gray matter alive remembering fishing knots,the tides and the names/uses for my box full of lures.

vac2018

09-01-2018, 04:47 PM

I am currently taking some welding courses, but it moved straight into more hands on training as opposed to classroom getting used to measurements, welding symbols, blue prints, exc. Coincidently, I am also taking a some advanced math courses to shore up those skills.

accounting jobs in UAE latest (https://www.vacancies.ae/jobs/accounting-jobs)

Any recommendations on the type of math I should gear up on? Trig, Geometry?

Go for geometry in this case.

Willie B

09-01-2018, 09:21 PM

I find that I use all 4 types of math addin miniusin timesin and dvidin

anything else?

Don't forget reconin' guesstimatein', and cipherin'

Virgil5

09-02-2018, 04:03 AM

High School geometry has gotten the job done for a lot of years for me, course I was Paroled from HS before Union Teachers came along or even the "New Math" so 2+3 = 5 in my world.

Tape measure and knowing 3 + 4 better = 5 if it's supposed to be a 90° corner will take most weldors thru a week in the real world.

Csquared = Asquared + B squared will handle most triangles and since pocket calculators came along all that square root calculating with a pencil went down the drain.

Knowing how to read a ruler is one thing I've seen wanting in young men and women for at least the last 2 decades. I'm not overly enthused by so called welding instructors spending classroom hours on trying to teach math or ruler reading that should be known and a requirement for admission to the welding class. Welding symbols are rarely going to be part of a weldor's employment for his or her first couple years. I favor more hands on time with a O/A torch and a stinger.

In 2018 I have yet to find a young person without a Device in their pocket, and that little box will access most layouts and provide an on screen calculator faster than any young person can do the math. When you're getting paid by the hour no employer wants to invest in your math deficiency, especially when a calculator exists and is available. Instruction time would be better spent teaching new people about these calculators and how to use them.

You should learn to use a newspaper to find the center of a circle as you begin working in a shop, same with using a strip of paper to lay out 4 equally spaced holes around the circumference of a tube. Half of the job on the shop floor is about getting the job done profitably, or there won't be a shop for long.

Country Metals

09-02-2018, 08:19 AM

You wouldn't believe how many engineers are completely astonished that I can figure out the size of a blender shaft with a piece of wire. Obviously there is a margin of error due to standard is metric sizing, but all I do is run a piece of thin wire, flat baler string, piece of paper etc around a shaft, mark the same spot, flatten it out, measure between the 2 points, divide by pie, and you have your shaft diameter.... Now this method is very very accurate because 1/16" off actually measures .196" between points. Obviously it won't do thousandths, but if you need to know if it is 3 15/16" or 4" shaft. 3 15/16 would measure 12.37" and 4" would measure 12.566" so huge gap for to guess the correct measurement.

This comes in handy when your calipers or special shaft measuring device is 20 minutes away and down 3 stories.

Sent from my 2PS64 using Tapatalk

MinnesotaDave

09-02-2018, 12:11 PM

Don't forget reconin' guesstimatein', and cipherin'

Measuring tools are important too - I use a calibrated eyeballometer :)

It even works for level and plumb, unless I'm standing crooked...

Virgil5

09-02-2018, 01:10 PM

You wouldn't believe how many engineers are completely astonished that I can figure out the size of a blender shaft with a piece of wire. Obviously there is a margin of error due to standard is metric sizing, but all I do is run a piece of thin wire, flat baler string, piece of paper etc around a shaft, mark the same spot, flatten it out, measure between the 2 points, divide by pie, and you have your shaft diameter.... Now this method is very very accurate because 1/16" off actually measures .196" between points. Obviously it won't do thousandths, but if you need to know if it is 3 15/16" or 4" shaft. 3 15/16 would measure 12.37" and 4" would measure 12.566" so huge gap for to guess the correct measurement.

This comes in handy when your calipers or special shaft measuring device is 20 minutes away and down 3 stories.

Sent from my 2PS64 using Tapatalk

Pie should NEVER be divided, unless it's mincemeat. If it's mincemeat don't even call me for pie.

Each person should be given their own pie. It's the decent thing to do.

CrookedRoads

09-02-2018, 02:37 PM

I have standard and metric tapes but still need to get one of these.

https://www.amazon.com/Muff-Products-Landing-Measuring-Measure/dp/B01NASTL52

ronsii

09-02-2018, 03:02 PM

Speaking of tapes... you wouldn't believe how many people on job sites think metric and engineers tapes are the same. :dizzy:

Virgil5

09-02-2018, 07:57 PM

Speaking of tapes... you wouldn't believe how many people on job sites think metric and engineers tapes are the same. :dizzy:

That kind of thinking should be encouraged. Given how few people know there are 12 inches in a foot, watching a layout done with an Engineer tape might be very entertaining.

ronsii

09-02-2018, 08:48 PM

That kind of thinking should be encouraged. Given how few people know there are 12 inches in a foot, watching a layout done with an Engineer tape might be very entertaining.

I always grade with the tenths, so we had some mud guys setting forms the other day... Well one of em' had gotten hold tenths tape somehow ��... After about five times of marking things wrong he finally chucked it in the bushes ��

pat h

09-02-2018, 08:51 PM

I have standard and metric tapes but still need to get one of these.

https://www.amazon.com/Muff-Products-Landing-Measuring-Measure/dp/B01NASTL52

It's ok but I didn't see the rch scale on it

Hankdelroy

12-05-2018, 09:37 AM

There are lots of online resources - just do a search for learning math and you will get a bunch of hits. Just don't let anybody sell you anything you don't want to buy. math.com looks like an OK place to start, but there are many places you can go to that have tutorials etc.

I’m studying engineering at college and I have a lot of math during the week and it would be naive, of course, to believe that it’s possible to learn math following tips or online examples. But occasionally its possible to find solutions at the field level and deal with separate assignment using calc, mobile apps or online helpers like this assignment.essayshark.com/math-help.html (https://assignment.essayshark.com/math-help.html)

docwelder

12-05-2018, 10:10 AM

Speaking of tapes... you wouldn't believe how many people on job sites think metric and engineers tapes are the same. :dizzy:

i've run into people who claim to be in the building trades all their life and can't read any kind of ruler. i saw this with my own eyes;one guy must have been about 40 and got into the union on some special program would match up bolts to his tape and put a mark on it.

MinnesotaDave

12-05-2018, 01:29 PM

You wouldn't believe how many engineers are completely astonished that I can figure out the size of a blender shaft with a piece of wire. Obviously there is a margin of error due to standard is metric sizing, but all I do is run a piece of thin wire, flat baler string, piece of paper etc around a shaft, mark the same spot, flatten it out, measure between the 2 points, divide by pie, and you have your shaft diameter.... Now this method is very very accurate because 1/16" off actually measures .196" between points. Obviously it won't do thousandths, but if you need to know if it is 3 15/16" or 4" shaft. 3 15/16 would measure 12.37" and 4" would measure 12.566" so huge gap for to guess the correct measurement.

This comes in handy when your calipers or special shaft measuring device is 20 minutes away and down 3 stories.

Sent from my 2PS64 using Tapatalk

The logging diameter tape, also called a DBH tape (diameter at breast height) does the computation for you.

It is marked with the diameter measurements when wrapped around the tree.

Way too easy though ;)

Bonzoo

12-05-2018, 05:25 PM

If I wanted to learn the math for pipe fitting what would be a good source to read or what books would be the best to read?

2 pieces of good straight angle iron, 4 clamps and go after it.

Rick42

05-01-2019, 10:06 PM

Problem solving. It is core to all problems. Find projects and work through the details, with an eye towards finding good techniques. This will help build core skills.

Work through a regular high school math curriculum, with a focus on word problems. They may seem lame, but they train thinking skills.

And learn to use a computer spreadsheet. They can be useful when working out something complex, like spiral stairs.

For example: If you lean a 15' ladder against a 12' wall, how far can the foot of the ladder be from the base of the wall?

Munkul

05-02-2019, 03:13 AM

SOHCAHTOA

was a word printed in large letters across the wall of our maths classroom. After the first couple of years I knew I'd never forget it :)

Sine X = O/H

Cosine X = A/H

Tanget X = O/A

SOHCAHTOA

Average spoonfed fabricators will rarely need trig, as drawings are so good these days, and tricky parts are often CNC cut these days.

Good fabricators will definitely use trig and geometry :)

+1

Kahn academy is a good way to improve basic skills.

It will not give you practice in creative, career oriented, problem solving - but is a great skill builder.

i dont like kahn academy. just try maybe...

https://www.youtube.com/user/MindYourDecisions

will help build your intuition.i used to watch some of it back in the day.... all u need is an ounce of intuition and u can figure out anything in the world, even make up your own formulas. Maybe a little more than an ounce, but you get the idea. That kahn guy drives me crazy, ooph..

And if your feeling over the top, try 3brown1blue or numberphille , but if you dont get it, downt worry, i really dont understand much of 3brown1blue, a little over my head sometimes, just watch it too help your visualization/intution/spatial skills https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw/videos https://www.youtube.com/user/numberphile/videos

remeber, its all about visualizing stuff, then everything else will click and fall into place, rather than blindy trying too look at a bunch of videos on a bunch of different math topics, when they are all very similar. Also if its daunting, dont worry, youll get there with enough practice, i promise, just like welding, in a sense. We are all in the same boat I am trying to learn some of the strength of materials stuff/beams/columns/shear in the machinists handbook and it is crazy complicated. But most of the times, u can get by with a little guesswork and trial and error then pulling out a fancy formula, except the times when its worth its weight in gold.

jrporter

05-20-2019, 10:30 PM

The logging diameter tape, also called a DBH tape (diameter at breast height) does the computation for you.

It is marked with the diameter measurements when wrapped around the tree.

Way too easy though ;)

When I was working as a Liaison Engineer (writing repairs for rejectable aircraft parts) I got a tag for an out of tolerance anti-icing duct. The duct was around 6" in diameter, very thin walled (probably around 10-15 thou) and flexible. The inspector reported the diameter with a number that went out to 4 decimal places. I got excited thinking of the exotic piece of measurement equipment that could hold this duct round and read the diameter accurate to within one ten thousands of an inch. When I asked the inspector to show me he whipped out his "pi tape" and said he wrapped it around the pipe and got a number. It ended in a fraction, which he put it in his calculator - 4 decimal places!

When I was working as a Liaison Engineer (writing repairs for rejectable aircraft parts) I got a tag for an out of tolerance anti-icing duct. The duct was around 6" in diameter, very thin walled (probably around 10-15 thou) and flexible. The inspector reported the diameter with a number that went out to 4 decimal places. I got excited thinking of the exotic piece of measurement equipment that could hold this duct round and read the diameter accurate to within one ten thousands of an inch. When I asked the inspector to show me he whipped out his "pi tape" and said he wrapped it around the pipe and got a number. It ended in a fraction, which he put it in his calculator - 4 decimal places!

ooph. you guys are bringing me back to the horrors of sig fig math in chemistry last year.

Powered by vBulletin® Version 4.2.5 Copyright © 2019 vBulletin Solutions, Inc. All rights reserved.