1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Engineering tape measure?

  1. Sep 6, 2007 #1
    today i interviewed for a job and the guy said i need a 100' tape measure in tenths...what the hell does that mean? also, how does one go about using one?
  2. jcsd
  3. Sep 6, 2007 #2


    User Avatar
    Science Advisor

    I can't say that I have ever heard of one. The person is alluding to a regular tape measure that is subdivided into .1 increments in stead of 1/16th increments like a standard tape measure. The only thing I have ever seen in tenths is an architectural/engineering rule. A 100' measure will undoubtedly be of a cloth kind on a slightly large reel.

    http://www.chiefsupply.com/images/products/600/SECOHEAVY.jpg [Broken]
    Last edited by a moderator: May 3, 2017
  4. Sep 6, 2007 #3


    User Avatar
    Gold Member

    I've never heard of one either. My steel tape is 16', and the longest that I've ever seen advertised was 20'. I used to have one that belonged to my grandfather that was maybe a bit longer than that. It was indeed made of cloth, and came in a leather-covered steel canister with a winding handle on the side. It was made sometime in the late 1800's.
    Both steel and cloth have problems when you get beyond about 10'. Steel is okay over quite a distance as long as it's lying on a flat surface, but sags when spanning a gap. It takes one hell of a lot of force to pull it straight, so it usually reads higher than the actual distance. Cloth has the same basic problem, but also has a tendency to stretch, so it can give too low a reading. (That's regular cloth; I don't know about something like Kevlar or carbon fibre cloth.)
    For 100' measurements, I'd expect to see a laser or ultrasonic rangefinder in use.
    Last edited: Sep 6, 2007
  5. Sep 6, 2007 #4
    thats weird. when he said tenths he confused me by showing me an engineers ruler, which i have never used, and saying that i cant multiply something by something. but yea, there are a few 100' tape measures out there, but i havent seen one that comes in tenths.
  6. Sep 7, 2007 #5


    User Avatar

    Staff: Mentor

    So just use both to make what he asked for. Use the cloth reel 100' tape measure, and then use the engineering rule held up against the tape (aligned up with the foot where you are making the measurement) to get your measurement in 1/10 inch increments.

    Do I get the job? Oh, never mind, I already have a good one.
    Last edited: Sep 7, 2007
  7. Sep 7, 2007 #6


    User Avatar
    Science Advisor
    Homework Helper

    I can't imagine why you would want a 100' tape calibrated in tenths of an inch. That's trying to measure something to one part in 12000. A temperature change of a few degrees would give bigger errors than that, for most materials.

    But I could imagine surveyors and suchlike having 100' tapes marked in tenths of a foot, before the days of laser rangefinders.

    But then again, surveyors used to measure with jointed metal rods called "chains" which were one cricket pitch long. Hence the old length units of 1 chain = 66 feet and 4 rods, poles, or perches = 1 chain.

    And 10 square chains = 1 acre, of course.
  8. Sep 8, 2007 #7


    User Avatar
    Science Advisor
    Gold Member

    I have several 100' steel tape measures and one plastic. The plastic has one side in feet and inches and the other side in feet and tenths of a foot. The reason for the tenths of a foot is for measuring out and squaring up strings used to mark the foundations and footings for buildings. You can calculate the diagonal for checking squareness and read it out directly on the tape measure.
    To the OP: I'd imagine if you have to ask the question of what such a thing is, you won't get the job. Just being realistic.
    BTW, 'chains' are still used for surveying.
  9. Sep 8, 2007 #8


    User Avatar
    Science Advisor
    Gold Member

    " BTW, 'chains' are still used for surveying."

    Yep. I've used them. Lot of work though.
  10. Sep 9, 2007 #9
    Nah see. I assumed when he said tenths that it was 1/10 of an inch instead of 1/16 like on the usual tape measures. THEN, he busted out the engineering ruler and said something really weird to confuse me. He gave me the papers to sign for the job, but I don't think i am going to take it, on the account of it not having set hours, which doesn't go too well with my school schedule right now.
  11. Sep 10, 2008 #10
    engineering tape measures divide a foot into tenths and hundredths, not inches and fractions of inches. for example, if i were 6' 6" tall, i would show 6.50' on an engineering tape. engineering tapes are the preferred method of measure for all oilfield work when dealing with pipe lengths.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook