On 2011-07-14, Larry W wrote:
In article ,
HeyBub wrote:
...snipped...
Hmm.

If subject to too much torque, the aluminum wrench will bend, the iron
wrench will break. "Too much" is probably greater for the cast iron wrench.
How much greater, I know not, nor whether it matters in the real world.



Your conjecture seems logical but real-world experience is the opposite.
The aluminum wrenches will break, the "iron" ones will bend. We commonly
call them "iron" but I believe they are actually forged steel. Possibly
malleable or ductile cast iron would make a passable wrench, but not
common cast iron. Especially for a pipe wrench, one of the most-abused tools
there is. Cheater bars, slugging the handle with a hammer,(or another
pipe wrench!) pulling handle with a come-a-long, etc. I've seen plenty
of them bend, but few break. The aluminum wrenches will break far
more readily.

I believe that the iron ones are ductile cast iron. They do bend. My
iron one is slightly bent.

i