I'll make this short and sweet.

1) Is a zinc plated stainless steel fastener okay to use in aluminum?

2) I purchased 8.8 rated bolts at home depot for replacements. Is that stronger than the #6 bolts stock on the rx7? I don't think the japanese where using the standard back then.

3) What is the alternator bracket bolt size? Not the water pump housing side, but the 12mm on the adjustment bracket.

Danke

 

I've never seen a zinc plated stainless bolt.
Zinc plating is commonly used on plain steel hardware to retard corrosion which is not a factor with stainless.

That said, I put anti-seize on every piece of hardware I install, no matter if it's going into aluminum or not.

Most bolts on the car are not really highly stressed, so 8.8 should be fine.

IIRC, the adjusting bolt is a 8 x 1.25mm but I could be wrong.

 

1. zinc plated stainless????? zinc is used as a rust inhibitor, stainless is already resistent to rust so plating it would be a waste. zinc plated steal bolts OR stainless are fine to use in aluminum. Neither will gall (seize) with the al.

2. My guess is the 8.8s are stronger then the stock bolts but not quite sure. They where using JIS bolts back then I belive. (jap. indust. stand,??) I've used plenty of home depot fasteners over the years they are fine just remember the washers.

and a great place for bolts for our cars. http://www.nutsandbolts.com/metric-c-34.html


3. M8x1.25 I wann say 35-40mm if i remember right. Its the one that is up on a little "tower" right? in the middle?

 

Thanks for the input. I dont know why i said zinc plates stainless, I meant zinc plated steel.

Speaking of a good place to get fasteners...I have a fastenal store near my house. I am going to stop by there today. I saw online that they had the flange bolts like the ones that came stock on the car. Using a flangebolt removes the need for a washer.

AUGieDogie, I am talking about the adjustment bolt on the driver side/top portion of the alt. It is on a black adjustment bracket.

 

I just bought a whole ton of flange bolts / nuts for the engine bay from fastenal. They will most likely have to order them.


Metric Grade 8.8 is comparable to SAE grade 5
Metric Grade 12.9 is comparable to SAE grade 8