John, you make good points. This is why man invented different alloys
and manufacturing processes for nuts and bolts.
If you look at the suspension components in a car such as our
spridgets, you will see that they are either purpose built (fulcrum
pins, special washers, etc.) or SAE graded hardware. I found no
"ungraded" or mild steel fasteners on any part of the suspension on my
car, and she was a virgin when I got her. Even the seat slide rail
mounting bolts were grade 8s. So were the bolts attaching the
radiator and shroud assemblies to the front end, valance to fenders,
etc. if memory serves me correct.
I'm sure that I'm preaching to the choir here, but don't screw around
with this stuff. Match the hardware you replace with equivalent grade
components. If you intend to reuse hardware, clean it first and save a
lot of trouble. Look at the hardware. If it has been abused, the
threads will often be distorted. Throw it away before it hurts you.
Check with a thread gauge. Clean rusty fasteners by soaking in
vinegar, rinse, dry and brief application of the old wire wheel.
Run a tap through nuts and threaded holes. I know it takes time, but
it makes life so much easier, especially after a respray. Clean
mating surfaces (perhaps I should rephrase that bit) are critical to
proper tightening of fasteners. If you lube them, the correct torque
value changes. If they are full of debris, the correct torque will
likely snap them.
Never reuse nyloc nuts. Use the proper torque to tighten stuff up. Be
safe!
My opinions, anyway; and you know what they say about that!
Hal
______________________________ Reply Separator _________________________________
Subject: Re[2]: Fasteners!!!!
Author: <john.kahoon@pcohio.com (John Kahoon) > at ccout
Date: 1/15/98 5:28 AM
HC>ccout.genauto.com>
Hal Wrote:
HC> Grades refer to the tensile strength of the fastener.
HC> Bolts are generally marked with hashes on the head in a radial
HC> pattern, higher grades of fasteners having more marks, and more
HC> tensile strength.
HC> When you torque a fastener, what you are really doing is stretching
HC> the unit to its proper tensioned length, with the torque a convenient
HC> method of determination. This ensures that the fastener will not
HC> loosen inappropriately or fail due to over stress.
snip>
Folks, please be careful when screwing around with what the Engineers
did for you.
Some applications require the lower grade bolts...
Think about it, the harder the bolt ( higher the grade ) the more
brittle it is. There are some places where you don't want a brittle
bolt ! An extra high gade bolt on suspension parts may not be good,
an overload, and SNAP, were a lower grade would bend a little... See
my point ? The RIGHT tool, for the application, including fasteners
!
John Kahoon
71 midget ( stock fasteners :)
HC>______________________________ Reply Separator
HC>_________________________________
HC>Subject: Re: Fasteners
HC>Author: <jphender@soli.inav.net > at ccout
HC>Date: 1/13/98 8:42 AM
HC>Thanks for the advice Shawn,
HC>Can someone give a quick tutorial about "grades" of fasteners? What is
HC>unacceptable and why? Are they marked with a code? I don't think asking
HC>my local hardware guy would necessarily yeild a correct answer. I am a
HC>RELATIVELY bright guy, and I didn't even know I had a choice!
HC>The only thing I've used stainless on was the manifold/block and
HC>manifold/pipe junctions. Are there any others I should change before they
HC>freeze up?
HC>The "stock-up" list that Shawn started (may it grow ever more complete!)
HC>is great. There is a visible path from my house to the Coast-to Coast
HC>store. (My '87 horizon drips a bit. Who wants to work on one of those
HC>anyway!)
HC>Jim Henderson
HC>'69 Sprite MKIV HAN9U78817G
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