How is a micrometer used and read?

Question

I just bought a micrometer on eBay and it came without instructions. I am going to use it to determine the diameter of fishing line and need either instructions or a site to get instructions.

Answer 1

Allow me.

since it is a fishing string you are measuring it will most likely be under .050 of an inch thick.

A human hair is around .003 of an inch.

To start, close the micrometer, apply only light pressure. If available use the knurled knob, at the end of the handle.

Make sure it is zeroed out. The zero should point to a line scribed down the center.

Open them just enough to fit in the fishing line. Keeping in mind that each full rotation of the thimble is equivalent to .025 of an inch.

Now gently close the thimble, on to the fishing line, again use the outer knob if available.

Read the number that lines up with the center scribed line. If it reads "15", this measurement is written .015". If it reads "7" this measurement is read .007"

Now add this number to .025" for each complete turn the thimble had to make from zero.

If for example the number on the thimble reads "9" and you did not have to open it any complete turns: That would be (.000" + .009" = .009"

If on the other hand the number on the thimble reads "10" and you had to open it one complete turn: That would be (.025" + .010" = .035"

Hey you are on your way to becoming a machinist . Good luck !

Answer 2

Well, if your micrometer is an old-fashioned one like the type that is found in school labs, it works like this. It appears like a c-shaped clamp with a knob that can be turned. The reading is a combination of two things -- as you unscrew the knob, it uncovers graduations that you can read on the shaft. Second, there are finer graduations that give a fraction of a turn marked around the end of the knob. The two together are the reading. Now about STYLE. Always gently close the micrometer on the thing you are measuring. First, gently close it empty and record the reading. It ought to be zero but might not be if the micrometer has had some use. Now measure your object and subtract the zero reading to get the correct reading. You are now a pro.

Answer 3

first you need to calibrate it....gently close it all the way and make sure the zero markers line up if not there should be a tool (a small wrench with c shaped or semi circle opening that has a hook on the end) hard to explain how to read but I would measure things you already know their thickness or diameter and relate that to whats on the micrometer. .250 is 1/4 inch .125 is 1/8. ck out this site http://catalog.starrett.com/catalog/catalog/PLH2.asp?NodeNum=19000&Mode=REF

Answer 4

try this page:

http://regentsprep.org/Regents/math/tools/microm.htm