Shot peening and cryo treating

[Tim Rogers]

I wrote:
> fatigue limit of a piece of E4120
That should be E4130 steel.
You want someone who advertises that they can shot peen to "aerospace /
military specifications".
Smith says that the big reputable names in shot peening 18 years ago were: The
Abrasive Finishing Company, PeenRite, and The Metal Improvement Company.  Each
has offices throughout the country, but they are widely spaced.
It would be best to be able to talk to "The Man" at the location you are
dealing with.  That does not mean the order writer (usually).  We are talking
about the guy who has been in the biz for a while, has seen and done it all,
and hopefully has some true engineering experience.  You know, a Mike Kojima
of the shot peening world :-)
It would be best to be able to tell "The Man" you are dealing with:
- What the material is.
- What hardness it is heat treated to.
- What surfaces must be masked.
- What kind of loading the part will see - tension, bending, compression or
torsion.
- What the general failure mode is....
And then let him tell you exactly what should be done, because if you try to
show him how smart you "think" you are, you're probably going to piss him
off...
And when you find the right guy here in the Atl. area, remember if he does a
good job, because we'll need to use him again when you rebuilt my gearbox for
my ITS NX2000 :-)

Tim Rogers