>On Thu, 26 May 1994 rhamilto@fox.nstn.ns.ca wrote:
>
>and was very gentle in response to my smart alecky comment. Originally,
>he said:
>
>> >
>> >> About fifteen years ago while employed in building railway freight
>> >> cars, we had a salesman demonstrate the reason to use new bolts instead
of
>> >> the ones removed especially where there is concern about the
compression
>> >
>
>I began to think about this. Torquing a bolt presumably elongates it, and
>the axial force clamps the pieces together. Details aside, I wonder if
>one is really concerned about the clamping force in most automotive
>applications. In other words, in automobile uses (con rods, for example),
>does one torque the bolt to specs in order to generate sufficient clamping
>force, or to keep the bolt from spontaneously coming loose? I would
>suspect the latter.
>
Ray,
I really got a chuckle from your first reply. ;-) I have to agree
with you on the con rod bolts but I would think that in the case of head
bolts, that the clamping forces would be more important in order to make sure
the head is seated properly on the block and compressing the head gasket
properly.
Bob Hamilton (rhamilto@fox.nstn.ns.ca)
Waverley, Nova Scotia.
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