Gunner Asch on Sat, 28 Jun 2014 10:34:18 -0700
typed in rec.crafts.metalworking the following:
On Wed, 25 Jun 2014 14:16:04 -0400, Randy333
wrote:
He would be correct should the specific job -require- certs, but for
anyone else and at any other time, it's not a problem. I think most
of us tend to overbuild, so unless a specific high performance is
absolutely required of the part, it's pretty much a moot point.

I've never needed a cert in 20 years of being in this business, but I
do not do any work for anything that drives or flys.

Never seen a cert at my last job either.

The metal suppliers I deal with all want extra cash for certs. I just
say no.

Client of mine just made 800 parts out of 4140..nicely done..and had
them rejected.
Cause?

Material melted in the UK, but formed into bar stock in the US.

Materials supplier sold them "US" steel..but Boeing rejected them
because of the original source of the melt.

Client has to eat the costs.

And make new ones out of approved material.

In some fields, it may not matter what the material actually is.
In other fields ....
Aerospace is one of those "other fields". In theory, when an
airplane fails, the part which failed can be traced back to who put it
on the plane, who inspected it, who made it, who signed for the raw
materials, who shipped the raw material, which heat lot it was from,
and who dug it out of the ground.

In the "great stories" I have heard: The school got a great deal
on high grade SS pipe. Originally intended for some nuke power plant.
But, the guy unloaded the pipe and then backed his truck out of the
lot, before handing the paperwork in. By the time he got back in the
lot, the QA guy was out with the can of red paint writing "Scrap" on
the entire lot.
The other, related story, was of Inspector Dick, who finally
"caught them". Seems that the guy had cut a chunk off the billet,
without first transferring the heatlot number from the corner to be
cut off, to the rest of the billet, thus "breaking the chain" of
accountability. Yeah, a technical matter, but if you are not
responsible in small things, why trust you on the larger ones?
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."