Quote:
Originally Posted by Hydroglen
Wheels have been tightened by hand around the world for some 80 years, and I have certainly never come across this issue except on this Forum!
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And it seems wheels have also been falling off cars for years!
It's only ever happened to me once, but once is enough to get you thinking about it. However, as I said at the beginning of the thread, the topic has come up as the subject of a dispute in which I am being told it's my fault because I didn't supply the official (Bristol factory) torque specifications for the wheel nuts!
While this cannot possibly be used as an excuse by the mechanic involved, I do however think it is a valid question, because there
will be a minimum torque figure. It may be Dorien, that you always comfortably exceed that figure when you tighten your wheel nuts, but does everyone? Or are all the stories of wheels falling off are down to the nuts not being under any torque at all?
Quote:
Originally Posted by RGSchmitt
I recall there are standard values for torquing bolts, based on bolt grade, size, etc. Such as
BOLTS AND TORQUE SPECS
And there is a well known book among racers only on fasteners, by Carroll Smith.
Anything similar for other graded, non-US fasteners?
Bob |
Bob, I have Carrol Smith's book (thanks for reminding me) and it quickly becomes clear that there are so many variables that it would be impossible to list all the recommended torque values.
As an example, there is a table in the book titled "
Recommended tightening torque for AN-3 through AN-20 and AN-73 through AN-81 bolts."
Below the table is says "
All values are for clean and dry cadmium plated nuts and bolts without a lubricant. Use of a thread lubricant will make these values invalid".
The point being, that not only do recommended values change when using a lubricant, but they change for every different type of lubricant!