School me on types of metal and their strengths

[thatK30guy]

Such metal as 4340, 4140, etc.
What about aluminum stuff like 6061-T6, etc.

I'd like to know simple stuff of the certain types of metals like the PSI or weight ratings, etc.

Simple things like can 6061-T6 be used to make zero-rates? Why some metals are better to use than others.

Turn this post into a simple learning thing for the dummies like me.

 

[Masiony]

try this: http://www.pirate4x4.com/tech/billavista/PR-BV60/index1a.html

 

[thatK30guy]

Damn! Thats some detailed and looooooooooooooong reading!

 

[tRustyK5]

it's a detailed and looooooooooong subject.

Rene

 

[thatK30guy]

I knew you would reply to this thread.

I didn't see anything about the characteristics of 6061-T6 which I'm seemingly so hard on about.
What can you tell me about this aluminum shiznitz?

 

[13lazer]

an easy thing to remember is as strength in psi increases, so does brittleness. stronger and harder steel is more sensitive to cracking. gouges and scratches are much more serious on a part that has been heat treated or hardened, like a grade 8 bolt.
softer lower strength material can bend more before becoming damaged. less likely to crack and is less sensitive to notches, but more weight is needed to increase strength.
aircraft need lighter high strength materials. aluminum is very strong by weight, its also much more expensive. stainless steels are alloys of steel with higher percentages of chromoly and manganese among other things.
structural steel shapes are quite low strength compared to other metals. yield strngth between 36k and 50k. the crappiest eastern european rebar yields between 55k and 80k.
my father is a metallurgical engineer so i have absorbed alot of this stuff, i've been involved with metalworking since i was 12 and my dad had me cutting and polishing weld cross sections so he could look at them under a microscope.
choosing the correct alloy for an application is best left to engineers, especially if materials beyond simple structural steel are needed.

 

[tRustyK5]

I knew you would reply to this thread.

I didn't see anything about the characteristics of 6061-T6 which I'm seemingly so hard on about.
What can you tell me about this aluminum shiznitz?

Although 6061-T6 is quite strong there are applications where I wouldn't use it. A zero-rate is one of those applications. It could potentially see a real pounding as a bottom leaf and would work harden and eventually crack. As a 1" body lift it's an awesome material...same deal with adaptors and bearing retainer housings (see NWF's newest parts for an example).

The problem I see with steel and aluminum as far as judging whether or not it's a good choice is that there isn't any real clue when reading the numbers that stuff is called. There are so many different society's labelling stuff with their own system you really do need a huge book to first decipher it, then compare it to others. Then even after that you really should have some engineering school behind you in order to choose wisely. There are literally thousands of different steel alloys, and quite a few aluminum alloys to choose from. Each has it's ideal intended use and strong point as well as it's drawback.

Bottom line is that without a much better education that I can't really give you a better answer. I wish there were some easy rules of thumb or easy decoding but there just isn't.

Rene

 

[AussieK5]

I'm in the last year of my Aero/Mech Eng degree and the best advice I could give you is what Rene said.

I wish there were some easy rules of thumb or easy decoding but there just isn't.