I’m getting back into rebuilding my 82 and want to get hardware that is as correct as possible. Is there a way to decode the factory part numbers into hardware sizes or do I have to get a bunch of different bolts and screws and see what fits where? Any help is appreciated.

 

It is possible to decipher standard bolt and screw sizes.

The first 5 digits are a style code, usually beginning with a 9, eg 9078-6x-xxx is a bolt with washer. These style codes are not decipherable, but you can infer by cross-referencing against other known fasteners.

The next 2 digits are the diameter (JIS metric) eg 08 is M8

last 2 digits are the length, eg 20 is 20mm long

So, 9078-60-820 is a 20mm long M8 bolt with washer.

If there is no letter suffix in the part number, it is usually a zinc plated part. Anything made pre-year 2000 or so will be gold/yellow passivated zinc. Anything later will be a silver colour, as they phased out the carcinogenic gold colour from the plating.

If you add a B at the end, then it is the same bolt or screw but in black oxide.

There's a bit more detail written up in this thread here: https://www.rx7club.com/3rd-generati...1155090/page2/

...and elsewhere on the forum

 

Thank you so much! I tried searching around the forum and looking at other websites and couldn’t find it.

 

Awesome post with info KYPREO.

Also I would like to add... and your Mazda dealer may think you are crazy, but for the more special/important fasteners, many of them are still available from Mazda as they have just carried that part along over the years.

ie can get many of the OEM bolts/nuts/washers for the rear suspension, watts link etc. And I am sure more if you look. Odds are if the part number shows as available in an online Dealer catalogue, your dealer can get it. I think thats pretty cool.

Also I found the best source of nice metric hardware to be Belmetric. They have everything.

 

Thank you! I used PartsVoice.com for a few bits of hardware and they didn’t show up. I’ll have to call each dealer individually.