Except in the case of a countersunk screw where the length includes the
head, ie for countersunk screws the screw length is the overall length.

Jeff Wisnia wrote:

Anon wrote:

does screw length include the part of the screw that is in the nut?

I need a tool to measure the length of a screw. I would normally say,
use a ruler. But my local DIY stores don't sell them, and the rulers
that stationary shops sell are no good because the 0 is not in line
with the end of it. I don't really want to get one of theirs and file
it down.
A micrometer would measure screw length including the nut, but not
excluding it.

How should i measure it, what product should i use and who sells it?!



I was tempted to think your post is a troll, but then I realized that
SWMBO might just ask the same kind of questions, bless her heart, so:

*****************

No, screw length does not include the nut. It is the length of the
screw measured from the underside of the screw head to the end of the
screw.

*****************

To make an accurate measurement,

Find someplace and buy a steel scale, like this one for example:

http://www.use-enco.com/CGI/INSRIT?P...PARTPG=INLMK32


Which, if you have a good eye, will let you measure the screw length
to 1/64" easily.

Or, if you want to "automate" your measuring, get one of these:

http://www.harborfreight.com/cpi/cta...temnumber=5647

Or go hi-tech and get one of these:

http://www.harborfreight.com/cpi/cta...emnumber=47257

(One similar that is fast becoming the most reached for tool in my
shop...Particulary as my eyes age...

****************

By the way, and just to be my PIA pedagog self, strictly speaking, a
"ruler" doesn't have any markings on it, it's a straight piece used
for drawing straight lines. (Like the ones on "ruled paper".)

The thingy with the markings and numbers on it is properly referred to
as a "scale".

HTH,

Jeff