turbo > cat bolts?

[Ameer Antar]

I picked mine up from McMaster's catalog. Their online pages have some good
info.
 
Basically, markings for metric hardware is very simple:
For steel: the class is written right on the bolt head or nut... e.g. 8.8,
10.9, 12.9
        8.8 is standard, 10.9 is for high-strength in suspension parts, and
12.9 is the most common socket head class
For stainless: there aren't classes, but type of material. The most common is
18-8, then 304 (A2), and finally 316 (A4)
        The bolts are marked either on the head or the end of the bolt; for
nuts they're on there somewhere.
 
If there are no markings, it's probably 18-8, but I wouldn't trust it. There
are a lot of places you can get these specialty hardware bits, but you will
have to buy in quantity. I can look to see if I have enough extra nuts/bolts. I
also have 316 rated studs I used for the wastegate.
 
-Ameer 


-------------------- Original Message --------------------
From: thejimrose [thejimrose at gmail.com]
To: Mark R [speedracer.mark at gmail.com]
Cc: Ameer Antar [antar at comcast.net], Quattro List [quattro at audifans.com]
Date: 3/20/07 1:43:12 PM
Subject: Re: turbo > cat bolts?

 anyone know of a good 'idiot's guide to fastener grades and markings' ?

thanx
jim

On 3/20/07,Mark R < mailto:speedracer.mark at gmail.com >
 wrote:I agree.  Regular stainless hardware in the stores is 304 series and is
roughly equivalent to grade 5 steel as far as strength.  For exhaust
installtion, this is sufficient.  The key is proper installation, gasketing,
and torque.  Personally, I'd use 316 series due to the heat.  The added
mechanical properties is a nice bonus, but I use 316 due to it's higher
resitance to corrosion in the high heat (and resulting condensation)
situation.ARP would likely have appropriate hardware, but that's overkill, I'm
sure.Mark Rosenkrantz

On 3/20/07,Ameer Antar < mailto:antar at comcast.net >
 wrote:I've used 316 (A4) grade stainless hardware and they've held up on the
turbo
and wastegate just fine. I used regular old 304 stainless (A2) on the cat. No
problems at all. Just make sure you don't use an impact wrench on these things.
Is your cat directly bolted to the turbo? Strange setup, but if it is,
definitely go with the A4 grade; these are supposed to retain their strength in
high-heat situations. If you need any I just may have some left over.


-Ameer


-------------------- Original Message --------------------

> Message: 5
> Date: Mon, 19 Mar 2007 22:36:28 -0700
> From: thejimrose [ mailto:thejimrose at gmail.com ]
> Subject: turbo > cat bolts?
> To: mailto:quattro at audifans.com 
> Message-ID:
>     [ mailto:298352bd0703192236r52a5da58u51053784b8012d63 at mail.gmail.com ]
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> anyone have thoughts on what to use for the bolts to attach my turbo to my
> shiny new high flow cat? the stock stuff is grade 8.8 black oxide. pretty
> standard. i'd like to step to stainless but it seems SS bolts are a little
> softer [ive broken a few].
>
> i got some SS nuts, bolts + washers from the local ace, but i NEVER want to
> do this job again so if there's a best grade or hardware to use, i'm al over
 > it.
>
> thanks
> jim
>
>
> ------------------------------
>
_______________________________________________
quattro mailing list
 mailto:quattro at audifans.com 
 http://www.audifans.com/mailman/listinfo/quattro 
---
 Watch this space for ads :)




--
--------------------------------------------------------
Chuck Norris counted to infinity. Twice.