20 hours ago, HS30-H said:

Let's take a look at the random example of a bolt from the front suspension. It's one of the hex bolts that holds the balljoint onto the transverse link.

Part number from the 1970 Nissan C-187 Parts Catalog for the S30 and PS30 models is: 81-30820-65 BOLT WITH WASHER.

Nissan Engineering Standard (NES) tables, the '81' prefix identifies it as a Hex bolt and the '65' suffix - when you look it up on the above table - shows us that it is Galvanized/Zinc Plated.

So far it appears that cadmium was NOT banned in Japan in 1970. Therefore it is possible that cadmium plated hardware was available in the automotive industry in 1970 and early 1971. Carl Back has evidence apparently obtained from a very reputable high level technology company, Honeywell, that cadmium was present on the hardware he had tested from 240Z's. It's not clear how much. Maybe a plating bath was contaminated and there was just a trace.

Mistakes happen, and sometimes deception. There are easily imagined scenarios where cadmium plated hardware could make it on to a 240Z production line, especially since cadmium was not banned and was still used in "more than 1,000 Japanese plants" in early 1971 .

At this point the argument is between what Nissan's documents say, and what Carl Beck observed, and what general public documentation from the time period describes. That's the whole thing in a single sentence. All that I've done is add a little bit of clarity. Forum members can draw their own conclusions.

The main point, Carl Beck's public service announcement, in a way, might actually be for people working with early 240Z hardware to assume that it might contain cadmium and to take appropriate precautions. Especially since the aftermarket appears to be offering cadmium plated hardware. Maybe Carl got some aftermarket bolts? Who knows.

https://www.zeddsaver.com/pages/about-us

https://www.nemetalworks.com/cadmium-plating-services

1 hour ago, HS30-H said:

Nissan Engineering Standard (NES) tables, the '81' prefix identifies it as a Hex bolt and the '65' suffix - when you look it up on the above table - shows us that it is Galvanized/Zinc Plated.

And therein lies the problem Galvanizing and Zinc plating are two totally different processes, the only thing they have in common is Zinc. If the Japanese specification is this vague then there will always be some confusion to what type of coating was used on the parts.

Coming back to the Vintage Z restoration program of 1996-98 in the USA; Nissan Motor Corporation USA was very specific that Cad plating be used and listed it repeatedly in their "Quality Control Checklist". They also listed suspension parts be painted semi-gloss black not powder coated. There is no confusion here, it's all in black and white on the document.