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RE: cylinder studs: torque or length?



Ben,
Between us tinkerers and the BMW Engineers I know who's advice I would
follow....

Just as an aside:
When angle torquing, in many appications, the material is taken to close to
yield point where the curve of increasing stress vs increasing strain
becomes more asymptotic to the strain axis.  This gives a more constant
"force" on the torqued item in service.  Now, using a torque wrench to get
to the same "force" is trickey because as the material approaches the yield
point there is less increase in torque proportionally as the nut/bolt is
tightened beyond that point - making the torque method (IMHO) a bit dicey
for important places where design engineers have decreed angle tightning...

Regards
Clive Liddell (only an EE so what do I know about elastic limits, limit of
proportionality, yield points etc?)
Pietermaritzburg, South Africa
'96 R850R ~81k.km
'01 R1100RT ~65k.km
=======================
> But my experience is that the low force primary setting is smeared all
> over the place due to the various draggy light forces which influence
> light torque settings. However, the variability of setting to say, 35
> ft-lbs is far smaller. True, you can turn the wrench until it just
> hits, say 20 ft-lbs and stop right there and go for a beer. But it you
> did it a second time or if you did it as the fourth stud instead of the
> the first, you might be in a quite different location. THEN you crank a
> substantial amount more.
>
> Marc is quite right to point out the original query had to do with
> studs. But the thread discussion seemed to veer off into the more
> challenging, divisive, and potentially very expensive issue of proper
> head torquing and so I took the liberty, perhaps wrongly, of proceeding
> there instead of starting a new thread.
>
>
> >
> > I will not even touch Ben's bait on  torque versus angle.
> >
>
> I think the term "bait" is very pejorative and is not merited by
> anything said or implied in my post. If anything, my intention was to
> present my views but to be clear that I knew that Tom - a person of far
> higher authority - didn't share my view of this very critical issue.
> Opinion differ on this one.

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