Chrome vs Stainless Steel

[Monkey Boy]

Aerospace process improvement...sounds like nice hi-tech stuff. Have you done any of that fancy 6-sigma / lean processing that Toyota are famous for? I kinda dabbled in it when I worked for Shell. I was also a materials and corrosion engineer but managed to get involved with other cool stuff too.I work for one of the other oil and gas majors as a trouble shooter / advisor in all things materials and corrosion. A job can come from anywhere in the world and it's Monkey Boy to the rescue but without the cool costume. Last week it was a job for Angola....next week it's offshore Indonesia

 

[Chris James]

Yeah, I am a six sigma greenbelt (I actually did the same training as the blackbelt and did more projects but they only wanted one 'blackbelt').

Not sure that what I currently do is hi-tec though! I used to work for a Rolls Royce sub contractor (we applied oxidation and corrosion resistant coatings to turbine parts) and would quite like to maybe try to get a job with R-R in a couple of years. My wife is pregnant with our second child at the moment so I don't fancy changing jobs just yet though.

 

[dubman]

R-R is a great place to work , loads of money for doing very little

 

[llllllll]

You need to define what you mean by "stainless" and "carbon steel". The former - 303/304 or 316? The latter, as drawn? How much carbon? Heat treated? And to what hardness?

A2 Stainless bolts (the most commonly found) are indeed "softer" than carbon steel equivalents. For example, the hexagon in stainless socket cap screws will wear out much quicker than their hi-tensile carbon steel equivalent (which are hardened), and for that reason don't find much favour in industry.

I'll have to bow to your superior knowledge, my post is based on personal experience (though reading it again it does come across as a touch arrogant ). My bolts are A4 stainless , which seem to be the only ones sold around here (not that I've looked very hard for any others). The reason I replaced the original bolts was that I ruined the heads by getting carried away with the allen key. I've had no such problems with stainless, though I have sheared the head off one by over tightening. I've also had to cut several to length and it's pain in the arse. It takes ages and I write off at least one hacksaw blade per bolt and Dremel cutting discs don't do much better. Perhaps the original bolts weren't hardened (???), but they were much easier to damage and I've never had any trouble cutting none stainless bolts.

 

[turbo tim]

316 (A4) stainless certainly is a bit of a bastard. I understand your problems with a hacksaw, you should try machining it all day long on a CNC lathe, murders the tools! It is hard certainly.

303/304 (A2) is pretty soft stuff by comparison, and certainly softer than high tensile bolts.

I'll look some figures when I get to work if I get the time.