Rockwell of Ford head stud nuts
 

Anyone know what the Rockwell hardness is of Ford's original head stud nuts are ? I had the plating shop that is Parkerizing them ask. Thank you Fordbarners.

Re: Rockwell of Ford head stud nuts
 

I'm not sure that info was available that far back??? IF anyone would know I suspect that DavidG or Kube would if they chime in. Based on the torque value of the head nuts at/or around 50 to 55 ft lbs I would suspect that it would be at least -OR- "similar" to what we use commercially called "B7" which is a "heat treated" chromoly 4140 steel, which is C35 (OR around that value at least). Just my theory!!!!

Re: Rockwell of Ford head stud nuts
 

Check out these Rockwell Hardness tester files:
https://www.amazon.com/dp/B005701LAG...itfrommetal-20

Re: Rockwell of Ford head stud nuts
 

I suspect they are nothing special, as they mangle pretty easy using stud pullers.

Ooops, didnt register stud NUTS not studs.

Re: Rockwell of Ford head stud nuts
 

Run a file across a nut and you will probably find they are mild steel. Or just tap one with a prick punch.
Doubt if Henry Ford or other manufacturers were using hardened nuts due to cost. Plus, they weren't needed. I bet lug nuts are the same steel as head nuts..

Re: Rockwell of Ford head stud nuts
 

I think he is asking about the head nuts.

Re: Rockwell of Ford head stud nuts
 

First thing I would do is ask the shop that is doing the process, why do they have to know that?
Pretty sure that the process does no subject the parts to any temperature that would alter their properties.
After all, didn't Henry do it to a lot of his parts? ( and probably never gave it a thought )

Re: Rockwell of Ford head stud nuts
 

Correct KGS, the nuts. If they were the equivalent of grade 5, they would be C32. From my knowledge of the manganese phosphate process, (Parkerizing trademark), the temperatures of the solution are not high enough to affect hardness. I will ask the question why.

Re: Rockwell of Ford head stud nuts
 

I bet the plating shop is concerned with hydrogen embrittlement and failure of the nuts, give then a call russcc, and see what they say.

Re: Rockwell of Ford head stud nuts
 

Good point Fordors. Have a question into them about why. It's a vary common process for firearms, so I would think there would be a concern for the application also.

Re: Rockwell of Ford head stud nuts
 

I´m with Fordors...they want to heat it up to drive out the hydrogen to avoid brittlement

Re: Rockwell of Ford head stud nuts
 

When I worked at EMD, GM’s former locomotive division, a friend gave me a Lufkin divider that was a bit rusty. I took it to the plating department and they gave it a bath in something and it looked like a new one when I got it back. First time I adjusted it the “C” shaped spring snapped like it was glass.

Re: Rockwell of Ford head stud nuts
 

Update. I spoke with the process engineer at the plating shop. The issue was hydrogen embrittlement. There is a pre & post process that neutralizes the embrittlement issue.