Rockwell Hardness of suspension bolts.

[Chuck S.]

Re: Rockwell Hardness of suspension bolts.

...As far as the thickness of the plating goes I've never measured it but after a short time you can see it building up on the copper wire and if you bend it enough it will peel like chrome on a bumper so I'm sure that the part have enough plating...especialy for the hard salty winters that the car will have to endure in years to come...

I'm sure when you get this baby finished, you'll be loath to take it out of the garage in the winter except on a trailer.

My comment wasn't directed as much to reduced corrosion protection as it was to explanation of the dull gray finish that resulted from brushing. It may be true that you are actually transferring steel from the brush onto the plating causing the discoloration. You might try brushing them with one of those fiberglass stranded wheels...it might brighten them back up without the "flash plating"; doesn't the "flash plating" take you back to needing to stress relieve them?

[Greg L.]

Re: Rockwell Hardness of suspension bolts.

Yes that may have been why they took on a darker tint after brushing. I only brushed the exposed areas and the shanks are still discolored from the baking so maybe I'll try the nylon wheel that came in the kit...it will be the first time I ever used it!

doesn't the "flash plating" take you back to needing to stress relieve them?

No I don't really think so... There are a lot of factors that contribute to hydrogen embrittlement such as, as we all know, the strength or hardness of the fastener. Two other factors that I can think of off the top of my head is the type of solution and the length of time in the solution. Cyanide based solutions increase the dangers of hydrogen embrittlement where as non cyanide based solutions like in the Caswell kit reduce the danger. Also my initial plating time before baking was about 3-4 minutes per part so it was fizing in the tank for a while. My little "flash plating" of 10 seconds or so should play well in my favor because of the very short time back in the solution.