Bob,
I totally agree. The real problem is the hard bolt sinking into the soft
aluminum. It only has to sink a couple of thousandths to remove all bolt
tension. The hardened flat washers spread out the load to help prevent
this. It also helps if the shock mounting holes are a snug fit on the bolts.
Dave Russell
BN2
Bob Spidell wrote:
> re:
>
> "I also use a flat washer, as well as a lock washer, ..."
>
>
> I gave this subject (fastening) a lot of thought and a bit of
> research and decided to clamp my shocks with hardened flatwashers and
> threadlocked bolts properly torqued. I have not had one come even
> close to loose on perhaps 40K miles (re-tourqed every 20K miles or so
> due to other work on the suspension).
>
>> From Carroll Smith's definitive book "Nuts, Bolts and Fasteners
>> Handbook"
>
> (originally entitled "Screw to Win," I have heard):
>
> "Neither the spring washer nor the wave washer do anything worth
> talking about--other than to provide the user with a false sense of
> security."
>
> --and--
>
> "Once compressed, the spring washer is nothing but a flat washer. If,
> for whatever reason, a bolt should loosen to the point where the
> spring washer opens enough to become a spring, there was too little
> residual stress in the assembled bolt for any sort of safety."
>
>
>
> Anybody use lock washers under head bolts/nuts?
>
> Smith does recommend star washers, in limited, small applications.
>
> If you wanted to use the "belt and braces" approach you could drill
> the heads of the bolts and properly safety wire two to each other.
> However, I believe once these bolts have begun to work loose it's
> only a (relatively short) amount of time before you have serious
> trouble ... the safety wire only buys you a bit of time, perhaps for
> a warning.
>
> I recommend the (late) Mr. Smith's book to anybody doing their own
> work. The non-glamorous business of properly fastening things
> together is quite possibly the most important and fundamental
> mechanical skill (I know in aviation it's a religion).
>
> Of course, everybody on the List has a set of quality torque
> wrenches-- preferably calibrated--right?
>
>
> bs
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