Micrometer types

[stevec]

Dave, I'm pretty sure the free digital caliper was included just to prove how much more accurate the micrometer is.

[roundrocktom]

Digging around the box

Photo with three mic's.
Top one I bought 30 years ago? Garage sale, no name but ball end made easy to check tubing thickness.
Brown & Sharpe -- love that one. Catch is the .025 reading is off, but mic comes in on 0.000 0 -- just an odd thing to remember.
Starrett - 1" to 2".
Standard and dowel pin match! HoloKrome dowel, handy reference.

1930's ruler. All used by my father circa 1936 @ Lockheed Aircraft.
Pioneer at top. Cool leather sleeve
Caliper of the day!
Skinny thick starrett - depth tool?
Wider Starrett

My first set of Calipers. Purchased in 1976. Rebuilding Rotary Mazda's Need to check crank journals and housings. Box is marked Craftsmen (where I bought all my tools -- it's been a while).

4 tio 5" Mitutoyo. Fine adjust was missing, but with a light touch worked fine. I was milling cylinder heads, needed something bigger than the Craftsmen set.

[roundrocktom]

Two More. Sorry about shawdows, I'm let the camera strap block the flash!

Mitutoyo Bore Gage... checking for taper during engine rebuilds!
Camera strap appeared!

Balls -- you don't see these much any more, but full set of std, +0.001 +.002 and +0.003. Handy if a hole is spec'd at -0 +2 thousands. Note inside lid, bought from S&R on March 1995. Doesn't seem that long ago. Tip, Machinery hand book is your friend when using these to determine intermediate bore size

VCI - Volatile Corrosion Inhibitor. McMaster Carr item. Pricey, but cheap insurance.

[TomG]

Nice collection.

Those gauge ball set are pretty handy. In addition to measuring the depth of cone shaped cuts like countersinks, you can also measure the pitch diameter of inside threads by combining them with a gauge pin. Think thread wires for internal threads.

Tom

[PixMan]

Can't those balls also be used to press through a bore .001" to .002" undersize with a rough surface finish and size the hole?

[roundrocktom]

(03-25-2014, 07:49 PM)PixMan Wrote: Can't those balls also be used to press through a bore .001" to .002" undersize with a rough surface finish and size the hole?

Correct. There are some rods shown that have a concave surface to go against the ball. Use an arbor press, and the correct ball... and that hole is dead on.

Article on ball sizing is here:
http://www.precisionballs.com/Ball_Sizing.php

[EdK]

Time to revive this old but interesting thread. I posted a picture of this micrometer some time back.

   

I finally got around to using it to measure my nuts.  

I'm not at all happy with the results. It's a Mitutoyo 103-114 with a plain thimble and no lock. When I remove the micrometer from the part I'm measuring the thimble turns all on its own. Not good. Checking Mitutoyo's web site, they don't even acknowledge that they ever made that model. That should tell you something. Anyway, I intend on replacing it with either a friction or ratchet thimble model and was wondering what type others like and why?

Ed

[Vinny]

I have the 103-136 which looks identical but has the lock. Then I also have a Lufkin with no lock. I don't recall ever using the lock.

[EdK]

(04-11-2015, 07:08 PM)Vinny Wrote: I have the 103-136 which looks identical but has the lock.  ....

That's the one I'm thinking of replacing mine with. The difference is the friction thimble versus the plain thimble. The plain thimble has very little friction to prevent it from turning so it's easy to get a false reading if you aren't careful.

Ed

[DaveH]

Ed,
I don't think there is much wrong with your micrometer, it seems just a little loose. There is usually a small threaded collar inside that will allow it to be tightened slightly.
 
DaveH