Why did this wheel stud break? Metallurgy issue?

[ollie]

While everyone has an equal right to post on BITOG, not all opinions are equally valid.

Some are derived from expertise in the field, and some are, well, worth what you paid for them, with variations in between those book ends.

If, for example, you're weighing an opinion on, say, the flight characteristics of a 767 between me, and a guy who's read about it extensively, and you consider both to be equally valid, then you're a fool.

Some opinions on this board are from experts, and some are from amateurs. Critical thinking is required to determine which is the more valid.

And some are not opinions at all. A little common sense and hands on experience go a long way. For me whenever I'm using an impact for tightening something like say my countershaft sprocket, I simply turn the air knob down. That way there is no chance of over torquing. I then finish it off with a torque wrench.

As far as my personal 25% torque eduction rule with lubricants. That has worked perfect for all automotive, generator, hydraulic, heavy equipment, general fabrication, and powersports. It's my experience and quite frankly, I can safely share it here on BITOG knowing that it will work for anyone else who uses it in the fields I described.

And Astro, as you very much know, aircraft is a whole different animal with any kind of wrenching. I would have no clue where to even begin!! You have FOD tools, safety wire tools that capture, and fasteners that are super critical. So of course torque specs for my applications are going to be thrown out the window.

 

[ABN_CBT_ENGR]

And some are not opinions at all.

I'm gratified to see you finally realize that

When you are told 2+2=4, is that a "fact" or an "opinion"?

Then "opinions" are judged/ranked according on the merits of the one offering the opinion, the information the opinion is based or shored upon relative to the situation at hand.

That means while all rights to have and share opinions are equal- the opinion itself may not be.

 

[Astro14]

I know only a little about aircraft maintenance. There are members here who are true experts in that field. I am not one of them. I fly airplanes, so can talk about how they fly.

I meant to offer me as an example of someone with first hand, extensive experience in a particular area, and then contrast that with someone for whom the area is one of interest, and perhaps, even experience, but not professional expertise.

So, forget me, let’s look at Trav, who is a master mechanic with decades of experience, day in, day out, turning wrenches. His posts are the result of expertise. Same is true of Clinebarger. CUjet knows a ton about airplanes from a variety of perspectives; owner, pilot, technician. Molakule has a PhD in chemistry and decades of experience in lubrication technology from a chemical engineering perspective. I read and respect his every post. JHZR2 has a PhD and a ton of practical experience in electrical engineering.

The list of genuine experts (in their field) on this forum is staggering.

In retrospect, I shouldn’t have chosen myself as an example, when there are so many better examples on this forum (and I’ve glossed over many for whom I have a great deal of respect).

We are talking about fastener strength in this thread. We have an engineer who tests fasteners, machines, and materials for a living. He has experience and expertise in this area.

To equate some modest degree of experience with breaking bolts or tightening bolts (and I’ve been doing both for over 40 years now) with his expertise is specious at best and, at worst, insulting.

Continuing the discussion past this point doesn’t make sense to me. The OP question has been answered as well as it can be.

The same points are being made over and over, but without any respect for the clearly expert opinion.