Noob question about steel

[joeyza]

so from what I understand, hardness of a steel has to do with edge retention - the harder the steel the better edge retention is that right? but if its too ahrd it gets brittle..
and the hardness that's measured by the rockwell hardness scale..
and then the toughness of a steel is to do with how much shock impact the steel can take before it gives correct?
if so then is there a measure or scale of toughness like the rockwell scale is for hardness?
please let me know if stuff i wrote is right or not and if not please enlighten me!
cheers

 

[idaho]

> if so then is there a measure or scale of toughness like the rockwell scale is for hardness?

No, there is no such simple scale.

> lease let me know if stuff i wrote is right or not and if not please enlighten me!

It is quite correct.

Here is very good basic free book about steel and metallurgy.
www.feine-klingen.de/PDFs/verhoeven.pdf‎
A must read.

 

[singularity35]

so from what I understand, hardness of a steel has to do with edge retention - the harder the steel the better edge retention is that right? but if its too ahrd it gets brittle..
and the hardness that's measured by the rockwell hardness scale..
and then the toughness of a steel is to do with how much shock impact the steel can take before it gives correct?
if so then is there a measure or scale of toughness like the rockwell scale is for hardness?
please let me know if stuff i wrote is right or not and if not please enlighten me!
cheers

There are other factors that contribute to edge retention besides hardness. Wear resistance, blade and bevel geometry, and edge finish are also factors.

The charpy v-notch is a test for impact resistance but I'm not sure if it indicates how well a steel will do in the toughness department as a blade.

http://en.wikipedia.org/wiki/Charpy_impact_test