- #1
thender
- 39
- 0
Hi,
I'm a mechanic and I need to settle a point with a fellow mechanic.
I was describing how a 3/8"s extension twisted during use, and I said maybe I need one that has been hardened properly. As in *through hardened*.
He said I am confusing hardness with rigidity. And to look into Young's Modulus.
From my perspective, rigidity seems to be something that goes hand in hand with hardening. Although it is not clear if there is a direct correlation.
What I am interested in is the angular deflection of a shaft from one end to the other when torque is applied.
I have looked into transmission shaft design criteria just a bit, but over there they are not so concerned with angles of deflection as much as the ultimate yield strength and fatigue failures.
Drill bits I believe are quite hard, and through hardened. Quite brittle too.
An automotive drive shaft is not very hard at all, certainly. But has a great deal of torsional rigidity.
If you can't increase a shaft's torsional rigidity by hardening it, well then how do you do it? Keeping the dimensions the same, is there a materials change or heat treatment change to be done?
Thanks,
I'm a mechanic and I need to settle a point with a fellow mechanic.
I was describing how a 3/8"s extension twisted during use, and I said maybe I need one that has been hardened properly. As in *through hardened*.
He said I am confusing hardness with rigidity. And to look into Young's Modulus.
From my perspective, rigidity seems to be something that goes hand in hand with hardening. Although it is not clear if there is a direct correlation.
What I am interested in is the angular deflection of a shaft from one end to the other when torque is applied.
I have looked into transmission shaft design criteria just a bit, but over there they are not so concerned with angles of deflection as much as the ultimate yield strength and fatigue failures.
Drill bits I believe are quite hard, and through hardened. Quite brittle too.
An automotive drive shaft is not very hard at all, certainly. But has a great deal of torsional rigidity.
If you can't increase a shaft's torsional rigidity by hardening it, well then how do you do it? Keeping the dimensions the same, is there a materials change or heat treatment change to be done?
Thanks,