I would say to some one that didn't work in metal that tape measures are for
carpenters and the best you can expect is 1/8" accuracy.
That being said I use tape measures often to rough cut bar stock, so I have
given some thought to this.

Accurate tape measure lay out has two issues, accuracy and lay out
technique.

Accuracy
A tape measure is a step above a yard stick in accuracy. The tape measure
has a hook that defines the point that the measurement starts from but has
big fat lines that define the increments of measure.
The typical tape has as it's finest division 1/16" (0.0625).
You are asking for lay out at the absolute limit of accuracy of the gage
supplied.

Technique
Okay, so maybe you want +/- 1/16"
That is reasonable, 2x limit of accurate measure, but how do you mark the
measurement?
A pencil and by eye?
Where does the scale define the point from which the measure should be
marked?
If you use the scale on the tape, the division lines are ~.02" wide and use
a blunt marking instrument will be a problem.
An imprecise scale and an imprecise marking tool would be for me with my
eyes at my age ( 50 ) a problem if there was pressure to hurry up and get it
done.

My solution:

I am a big fan of the Starred digital tape measure.
It reads to .05" in inch and 1 mm (~.040") in metric.
It calibrates the point of measure, from the hook to the body of the
housing, well enough for me, I find it to be about accurate to .025" and .5
mm (~.02") ymmv.
That covers the issue of accuracy
As to how to lay it out...
The problem with a tape measure is marking the point of measurement.
I use a shop square to determine the point of measurement, defined as the
distance from the hook to the body and make the mark with a sharp point.
hope you don't fire anyone
Kent
Where in Ohio is Ohio Brush?


"Tom Gardner" wrote in message
...
After 3 major measuring screw-ups this week I put 3 employees on notice
that
they had one month to learn to read a tape measure or...else. They are
60,
55, and 45 years old. How they got through life so far is beyond me. I
have tried to make go/no-go gauges for everything but this basic skill is
still needed and I can't be everywhere. I know I've been down this path
before and I'm so embarrassed that I still haven't been able to teach this
on this level. I have yet to find instructions for tape measures. I only
want 1/16" accuracy. Any thoughts?