RE: Spark plug socket

[gator@xxxxxxxxxxxxxxx]

In re-reading the original there are some issues I take issue with. strain
gauge. If a torque wrench is off by (X) because of friction then a strain
gauge will be off by the same (X). In a controlled environment a strain
gauge is difficult to use. In a practical environment it is next to
impossible, any none perpendicular pull is error plan and simple.
Gator in Dallas

>> If you use a good quality torque wrench correctly I think you will find
>> that accuracy is much closer to +/- 4%.
>> But that requires you know how to use the correct (as in have more than
>> one) torque wrench.
>> Gator in Dallas
>>
>> > gator@xxxxxxxxxxxxxxx writes:
>
> Two different issues!  Yes, a quality calibrated torque wrench used in the
> proper range will measure the torque applied to within a few percent, but
> the preload applied to the mating surfaces can still vary by 30%.  Why do
> you think the torque for the head bolts is specified as x Nm + y deg?
> Because turn of the nut applies a more consistent preload to the mating
> surfaces than simply measuring the torque applied to the bolts.
>
> Davis Eichelberger
>
>
>
>
>
>
>> >  > Just my .02 but I think that is the most rediculass thing I can
>> think
>> > of.
>> >
>> > Hmmm, you might be surprised.   There's a table on page 1404 of
>> > Machinery's
>> > Handbook 25 that notes the accuracy of bolt preload methods.  They
>> list:
>> >
>> > By feel +/- 35%
>> > Torque Wrench +/- 25%
>> > Turn-of-nut +/- %15%
>> > Preload indicating washer +/- 10%
>> > Strain Guages +/- 1%
>> > etc.
>> >
>> >  > Might be a good gouge when you don't have a torque wrench, as is
>> the
>> > tool
>> >  > kit when you don't have real tools..
>> >
>> > If the handbook is to be believed the turn-of-nut method is more
>> accurate
>> > than a typical torque wrench (when both are used by a typical mechanic
>> :-)
>> >
>> > // marc

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