Definition Of Hardware Protective Coating Codes

[69S-S/R]

God Evening One and All,

Can someone provide an explanation of the protective coating data as specified in the 1964 and 1966 911 Parts Manuals and offer acceptable coating substitutes which are available for each?

There seems to be a prefix code, i.e.: SW, ST, 4S, 5S, 6S and 8G, as well as the plating type, i.e.: bost., verz. and phr and there may be others. I am of the opinion that most engine hardware and plated parts are clear (silver) cad and that most hardware is either clear zinc or black oxide but how do these relate to the codes?

Thanks in advance,

Tom Scott

[304065]

God Evening One and All,

Can someone provide an explanation of the protective coating data as specified in the 1964 and 1966 911 Parts Manuals and offer acceptable coating substitutes which are available for each?

There seems to be a prefix code, i.e.: SW, ST, 4S, 5S, 6S and 8G, as well as the plating type, i.e.: bost., verz. and phr and there may be others. I am of the opinion that most engine hardware and plated parts are clear (silver) cad and that most hardware is either clear zinc or black oxide but how do these relate to the codes?

Thanks in advance,

Tom Scott

Tom:

sw= schluesselweite = distance across the flats, what Harry Pellow calls ATF
ST unknown
4S, 5S, 6S all thread fit + black oxide (you may see in conjunction with 10K, cite me a part nr. by email and we can discuss)
8G = Pre DIN/ISO property-class for PSI of fasteners
bost= bostik endurion, very, very hard black epoxy
verz= verzinkt = galvanized (read as cad plated in those days)
phr= phosphate = parkerized

does this help? only took me five years to figure it out!

p.s. good on you for finding these easter eggs, this shows your attention to detail (well known based on your 356 rep)

[69S-S/R]

Absolutely YES, this helps a great deal. I have only one question, if verz is silver (clear) cad, what would be the codes, or abreviations, for clear zinc and for yellow (gold) cad?

Thanks again.

Tom

[304065]

Tom,

As far as I know the factory never specified the chromate conversion coating. My own view is that it's all silver until 1967 and then yellow after that. This is substantiated by the research of others who suggest that hexavalent chrome conversion coatings were not allowed by law in Germany until 1967 from a production standpoint-- which would explain why Weber parts, etc., made in Italy have it while the engine fasteners do not. Also, I pulled original nuts off of my engine with the 8G "V" headmark (no doubt for Verbus) and they had no trace of yellow. It is still a mystery and like all things Porsche there are exceptions to the rule.

[69S-S/R]

Here is some additional research I did about 20 years ago for 356 harware protective coating translations for the abrevaitions in the Porsche parts manuals, some of this should apply for 911.

Verz = "Plated"
Verzinkt = Plated with clear zinc
Verzchromt or Verchr = Plated wih chrome
Bost or Phr B = Bostik Phosphate, or black oxide
Phr E = Endurion Phosphate, this is a olive green color
Gelb Chromatiert = yellow zinc, or cad, chromate
Gal zn = Galvanized zinc

The question is when did Verz change from black oxide to zinc, or cad, and then to clear cad and yellow cad?

Tom

[69S-S/R]

I have discussed this mater with two of the world's most respected Porsche hardware plating experts, at least that is my opinion. The conclusions we reached are as I described above. Early 911's, 1964 to 1966, used clear or silver zinc, Verz or Verzinkt, for about 95% of the hardware, about 3 to 4 % were black ozide, Bost, and the remainder was silver cad and phosporic. The seat rails were cad but not the allen head screws. The parts manual suports this specifically, refer to any part in the DIN and you will see the plating used.

Thanks to all those who helped resolve this issue.

Tom