1965 upper shock bolt finish

[Joe L.]

Re: Hydrogen embrittlement

Craig-----

Yes.

[Eugene B.]

Re: Caliper mounting brackets?

Joe,
Regarding the caliper mounting brackets, how positive are you of your advice about having them annealed after plating? I'm certainly no expert, that's why I appreciate the discussion group so much, but here's my thought.

I now understand the embrittlement issue better, regarding fasteners. Bolts are under tensile stress when torqued and therefore affected by embrittlement. However, a caliper mounting bracket is operating under compressive stresses and I don't see that embrittlement is likely to cause failure.

If heat treating after plating is a critical, I'd venture to say that there are way too many restored Corvettes, hot rods, etc. running around on the roads that are unsafe!

I'm not giving you a hard time or doubting your knowledge, Joe. Just trying to make a point and raise the level of understanding a few notches.

Best regards,
Gene

[Joe L.]

Re: Caliper mounting brackets?

Gene-----

It's likely a bit less critical that a part like a caliper bracket be treated to eliminate hydrogen embrittlement than it is for fastners to be so-treated. However, the caliper bracket is subjected to many different stresses and forces and high strength is important. I would never even consider having a part like this plated unless the plater could properly anneal it.

As far as you're statement about a lot of cars on the road with high strength parts which have been replated but not annealed being unsafe, it's probably a very correct statement. However, and fortunately, most of the parts requiring high strength on a car are enginered to have strength far beyond what is normally required. So, even if the parts lose some of their original strength, they still have enough to avoid failure under normal conditions. However, they may have lost the "margin of safety" originally built into them.