High tensile bolts 8.8 v A2-70 stainless

I have just swapped the bolts on my Safety Devices role cage for stainless
(the old ones were rusty).

I then got thinking whether they are strong enough.

The original bolts are 8.8 grade and the stainless ones are A2-70.

Anyone know if this is OK, or should I go back to 8.8 grade..?

cheers

simon

--
Simon Coupland
Peak District, UK

Simon Hi,

I think that the best would be to ask SD themselves.
But I think stainless steel has a tendency to crack under load while steel
bolts warp and bend but do not break as easily.

Please let us know since I would also like to replace the rusty bolts on my
SD rollcages on both my Discos.

Alternatively why don't you use cadmium plated bolts?

Take care
Pantelis


"Simon Coupland" <[email protected]> wrote in message
news:[email protected]...
> I have just swapped the bolts on my Safety Devices role cage for stainless
> (the old ones were rusty).
>
> I then got thinking whether they are strong enough.
>
> The original bolts are 8.8 grade and the stainless ones are A2-70.
>
> Anyone know if this is OK, or should I go back to 8.8 grade..?
>
> cheers
>
> simon
>
> --
> Simon Coupland
> Peak District, UK
>
>

Pantelis,

I have sent a mail to SD, so I'll pass on their comments. (I assume they'll
say to revert to original spec as it would be a liability for them to say
otherwise).

I'll go to cad plated if that's the result of their comments.

cheers

simon

--
Simon Coupland
Peak District, UK


"Pantelis Giamarellos" <[email protected]> wrote in message
news:[email protected]...
> Simon Hi,
>
> I think that the best would be to ask SD themselves.
> But I think stainless steel has a tendency to crack under load while steel
> bolts warp and bend but do not break as easily.
>
> Please let us know since I would also like to replace the rusty bolts on
> my
> SD rollcages on both my Discos.
>
> Alternatively why don't you use cadmium plated bolts?
>
> Take care
> Pantelis
>
>
> "Simon Coupland" <[email protected]> wrote in message
> news:[email protected]...
>> I have just swapped the bolts on my Safety Devices role cage for
>> stainless
>> (the old ones were rusty).
>>
>> I then got thinking whether they are strong enough.
>>
>> The original bolts are 8.8 grade and the stainless ones are A2-70.
>>
>> Anyone know if this is OK, or should I go back to 8.8 grade..?
>>
>> cheers
>>
>> simon
>>
>> --
>> Simon Coupland
>> Peak District, UK
>>
>>
>
>

On Thu, 24 Jun 2004 09:28:51 +0100, "Simon Coupland"
<[email protected]> wrote:
>
>I'll go to cad plated if that's the result of their comments.
>
>cheers
>
>simon
Cad plating is now almost obsolete. Cadmium is either carcinogenic, or
poisonous, possibly both and definitely unpleasant.

Zinc plating is more readily available.

MAKE SURE bolts are de-embrittled after plating, otherwise heads can
mysteriously fall off a couple of hours after you tightened them.

David

Pantelis wrote:
"But I think stainless steel has a tendency to crack under load while steel
bolts warp and bend but do not break as easily."

This is true. Stainless should not be used on areas of stress. It will snap,
steel will bend.
--
Wolverine
Big Red '93 110 CSW

On or around Thu, 24 Jun 2004 08:46:11 +0100, "Simon Coupland"
<[email protected]> enlightened us thusly:

>I have just swapped the bolts on my Safety Devices role cage for stainless
>(the old ones were rusty).
>
>I then got thinking whether they are strong enough.
>
>The original bolts are 8.8 grade and the stainless ones are A2-70.
>
>Anyone know if this is OK, or should I go back to 8.8 grade..?
>

we did this a while back. If you can get A2-80 then they're nearer
8.8-spec. I doubt, however, that the strength of the bolt is that critical,
A2-70 are pretty close to 8.8 - the toughest bolts I've seen were marked
12.9, but I couldn't find any to replace 'em, and 8.8s in the same
application never failed.

Check with SD as was suggested, if you're not sure.

Interesting to note that the specification for seat belt bolts (7/16"UNF) is
designed to be OK even with mild steel bolts, which seems a sensible way to
go - you can never know that someone will replace a bolt with the same spec.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
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Long dead thread I know, but was searching for similar info myself and came across it, deciding it was an appropriate place to stick what I'd found......

Where can I use A2-70 Stainless Steel bolts ?

A2-70 can be safely used to hold car body panels and bumpers in place.
Wing bolts, hinge bolts, handles, locks, light fittings etc.
A2-70 can be safely used on non-mechanically loaded engine components where a clamping action is required.
Manifold attachment, ancilliary attachment, pipe clamps, flanges etc.
A2-70 can also be used for securing access panels, cover plates and accessory items to the vehicle.


Where should I NOT use A2-70 Stainless Steel bolts ?


A2-70 should not be used in heavily loaded mechanical or structural areas.

• Areas of direct loading on the suspension.
• Areas of direct loading on the steering column and linkages.
• Active engine componets (con-rods, crank shaft, clutch & power off-takes)
• Active gearbox and power-train components.

A general rule of thumb is that it's OK to replace 8.8 and lower rated nuts and bolts.

Any nut or bolt stamped with a 10:9 or 12:9 should be replaced with an identically rated (or higher) component AND NOT an A2-70 component.