I've got to disagree with Corey on this one. There are MANY different alloys
under the general term "Stainless Steel" and consequently many different
levels of yield strength, hardness, etc... Some alloys can be hardened to
the point that they are as strong and in many cases stronger than SAE Grade
8 hardware. It is quite true that alot of light duty SS hardware is only
about SAE Grade 2, which is why it is doubly important when using stainless
that you get it from a reputable hardware specialist and not just the local
Home Depot. I would estimate that over 90% of the hardware used in a typical
vintage vehicle's engine compartment is no stronger than SAE Grade 5.
Anytime hardware is replaced I think it's a good idea to be very sure that
you are using hardware that is up to the task at hand, especially in vital
component systems such as brakes and suspension parts.
Using an anti-sieze compound is a great idea in this application. Loctite
makes several compounds that will withstand 2400 degrees farenheit. I
believe their url is www.loctite.com
Just my 2 cents
~Mike Brooks
----- Original Message -----
From: <corey.sherman@rcn.com>
To: <triumphs@autox.team.net>
Sent: Monday, March 25, 2002 9:04 PM
Subject: Re: Exhaust manifold bolt clarification (2nd email)
> IMHO, I would NOT replace the bolts with stainless steel ("SS"). While
> some SS bolts may look nice and have an "anti-rust" appeal, there is one
> major drawback that one must consider when replacing a bolt... strength!
>
> Stainless is a series of alloy steels which contain at least 12% chromium.
> Such steels will not rust when exposed to weather. The most common
> stainless steel is 304 which is an 18-8 alloy containing at least 18%
chromium and 8% nickel. 304 is a non magnetic steel. The metric
> designation for 304 is A-2. Even more corrosion resistant alloys, such as
> 316, are available for high corrosion environments such as marine use.
>
> Because stainless steel is softer than other steels (it only seems harder
> because it work-hardens) it tends to gall or wear prematurely. Overall, SS
> bolt are rated Grade 2, sometimes 5, while SAE stardand is grade 8. When
> it comes to the engine compartment... items subject to considerable heat
> and vibration - use SAE 8.
>
> Check out http://www.waukeshafoundry.com/antigall.htm for a picture.
>
> A remember to always use anti-Seize or a similar product on the threads
> ;-)
>
> ________________________
> Corey Sherman
> corey.sherman@rcn.com
/// triumphs@autox.team.net mailing list
/// To unsubscribe send a plain text message to majordomo@autox.team.net
/// with nothing in it but
///
/// unsubscribe triumphs
///
/// or try http://www.team.net/cgi-bin/majorcool
|