torque wrench issues

"John B Slocomb" wrote in message
...
On Mon, 24 Apr 2017 22:17:14 -0400, wrote:

On Tue, 25 Apr 2017 07:42:21 +0700, John B Slocomb
wrote:

On Mon, 24 Apr 2017 19:51:41 +0100, "Benderthe.evilrobot"
wrote:


wrote in message
m...
On Sun, 23 Apr 2017 22:06:05 +0100, "Benderthe.evilrobot"
wrote:


"Emanuel Berg" wrote in message
...
I finally got the 1/2" torque wrench,
28-210 Nm, not even made in China, but in
Taiwan! Eh... I guess it depends who you ask if
that is China or not

It has a locking screw, a torque setting
handle, a scale (Nm as well as "FT-LB", some
English unit I take it?) - it also as a
locking lever on top just like an ordinary
ratchet, so it can go both ways, clockwise and
anti-clockwise.

The torques only work in the
clockwise direction. So if the
locking (ratchet) lever is set the other way,
it is just a ratchet, right? Well, in
the manual it says:

Note: Never use the torque wrench to undo
nuts, bolts or other fasteners as this will
damage the ratchet mechanism and the
calibrated settings.

So how does that add up? Is it only OK to use
the anti-clockwise pull to insert things, which
would require a left thread? (And it would be
just a long shaft, with the torque not
in effect.)

As for me, I don't plan using it for anything
but as a torque, because I have other, less
expensive ratchets and spanners to do the
everyday stuff. But of course, I'd like to know
what it means.

It also came with a certificate with data on
the calibration and in the manual it says it
should be recalibrated at least every
12 months.

Calibration is irrelevant if you don't follow the rules to the letter.

Most torque settings I've seen were for dry threads - any stray
lubricant
and you might even twist the end off at the correct torque.


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Torque specs vary considerably by application. Some are given as
clean and dry, some are given as lubricated with oil - some are given
cold, and others hot. That said, I personally have never run across a
torque spec that was so "close to the edge" that torqing with "stray
lubrication" would cause immediate failure of the bolt by twisting off
the end.
However, that said, most of my wrenching has not been on bicycles but
on automobiles and agricultural and construction equipment which may
be slightly more "overengineered" or "overbuilt"

Bicycles tend to have less things you can twist the end off.

Its common on motorcycles, but mainly pulling the threads out of alloy
castings. Its pretty rare to strip an engine down so far that you can
put
the castings in degreasing plant - torquing the engine case bolts with
oil
left in the holes is a very good chance of stripping the threads.

As for stripping engine bolts, the Honda factory used to install
fasteners so tight that a normal person couldn't get them out without
an"impact driver". A tool that I never even saw before the Japanese
invasion.

The lock washers were very effective where used, and the Phipips style
bolts were incapable of delivering enough torque to breat them loose
without camming out - the Hammer Impact driver solved that problem

I believe I've read that the "Phillips" headed screws in a Japanese
motorcycle are not actually "Phillips" but some Japanese standard that
didn't quite match the screwdrivers we had in the U.S. Which probably
didn't help either :-)

That's the *whole* cause - just grind a tiny bit off the point of the
screwdriver bit and it fits just right.