original specifications on bolt corrosion protection
 

Hi all
I'm slowly progressing with rebuilding my '55 XK140 and have a specific question on nuts and bolts. I'm trying to reuse as many of the old bolts as possible. Most of them are rusty so they need some treatment and corrosion protection. Now I'm wondering how they left the Jaguar factory back in 1955? I'd like to avoid using modern style galvanized bolts as this just looks bad on a restored car.
The bolts on the engine and gearbox seem to be browned (not sure if that is the right English wording) while some bolts on the chassis seem to be cadmium plated.

Is that a correct assumption, or am I completely wrong?

On my Citroen classics bolts are all yellow galvanized, but this is definitely not right for the Jag.

Many thanks,
Chris

The two basic systems for proofing steel bolts in the UK for automobile use was cadmium plating, now no longer used, and chemical blackening.
https://www.ecwilliams.co.uk/cadmium...%20permissions.
and
https://www.fastenright.com/specials...t%20reflection.

Ok, great thanks! I was not too wrong then with my assumption.
Just wonder why all the big part supplier are selling cheap blue galvanized bolts instead of (usually available) blackened bolts. Maybe its just easier for them.
One of my neighbors has a nicely restored E-type, but all bolts are blue galvanized. Looks like they came straight out of home depot. A complete no-go in my mind.

I'll blacken the engine and gearbox bolts, and see what I can do for the cadmium plated ones. Will need to talk to my galvanizing shop. Not sure if Zinc-Nickel is the best option here. Technically its close to cadmium plating, but for our cars looks are more important.

Cheers
Chris