I buy boxes, usually 100 at a time, of the common sizes I use, in plated
grade 8, and use them for everything that uses an external wrenching cap
screw (hex head bolt to normal people) outside of the engine. Often, I use
internal wrenching cap screws (Allen bolts) for various reasons, and just
about all internal wrenching cap screws are of extremely high quality and
strength, beyond grade 8 SAE, which is the highest SAE category. Inside
the engine, I normally use ARP bolts for critical fasteners like rod bolts,
mains, flywheels, etc., although I've been known to use L9 bolts for mains
in a pinch. If I can't get, or don't feel like paying for ARP, I use Allen
type bolts. I only use Nylock nuts, either grade 5, or grade 8 if I'm
nervous. I've yet to go to aircraft fasteners for anything. I also buy
boxes of grade 8 washers, to use in all washer applications, and I buy lock
washers designed to be used with Allen bolts if I use a lock washer in any
critical application, which I rarely do.
I lube all fasteners that I use a torque wrench on, inside the engine, with
moly grease on the threads and under the head. I use Loctite on fasteners
outside the engine only, if I think I need it (axle bolts, brake caliper
bolts, etc.,) only if I can't lockwire the thing.
When I building a street car, I tend to replace everything with the plated
grade 8 stuff, but forego the lockwire step, and just do the things up tight.
I offer this if anyone cares...
Brian
>
> Never use less than a grade 5 bolt (usually 3 hashes) on any
> automotive application and you should be safe. Internal engine,
> suspension and other strength-critical applications warrant more
> attention to detail. I used grade 8s when replacing the spring-pan HW
> on my front end and the brake backing plate HW on the rear axel, for
> example.
>
> I know there are a couple of MEs out there who will probably provide
> more info...
>
> Hal
>
>
>
>
>______________________________ Reply Separator
_________________________________
>Subject: Re: Fasteners
>Author: <jphender@soli.inav.net > at ccout
>Date: 1/13/98 8:42 AM
>
>
>
>Thanks for the advice Shawn,
>
>Can someone give a quick tutorial about "grades" of fasteners? What is
>unacceptable and why? Are they marked with a code? I don't think asking
>my local hardware guy would necessarily yeild a correct answer. I am a
>RELATIVELY bright guy, and I didn't even know I had a choice!
>
>The only thing I've used stainless on was the manifold/block and
>manifold/pipe junctions. Are there any others I should change before they
>freeze up?
>
>The "stock-up" list that Shawn started (may it grow ever more complete!)
>is great. There is a visible path from my house to the Coast-to Coast
>store. (My '87 horizon drips a bit. Who wants to work on one of those
>anyway!)
>
>Jim Henderson
>
>'69 Sprite MKIV HAN9U78817G
>
>
>
>
>
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