[totaldla]

Originally Posted by dacaur

Other than abrasion resistance, where cast iron wins vs aluminum, The really important quality here is fatigue life. Steel and cast iron have a much longer fatigue life than aluminum. What that means is that with steel and cast iron, as long as you dont exceed its structural strength, cast iron or steel will last somewhere in the order of hundreds of times longer than aluminum. (Not hundreds as in 100-500 more cycles, if aluminum lasts 5x10 to the seventh power cycles, steel or cast iron will last 100-500x10 to the seventh power cycles) Take 3 bars, one steel, one cast iron, and one aluminum, and put bending pressure on them equal to half their strength, then release, then repeat that over and over. Steel and cast iron will go on MUCH longer than aluminum millions of cycles more, despite the fact that you are not even really straining it. Aluminum has the lowest fatigue life of any metal out there. This is why airliners, which are mostly aluminum, have a service life, that once it passes a certain number of takeoff/landing cycles, its scrap, because the aluminum skin can only handle so many pressure cycles from gaining and losing altitude.

I'm not saying you will ever break an aluminum press, just that the aluminum one WILL break before a cast iron one, barring abuse.

Chances are the ram going up and down will wear out the aluminum before it ever reaches its fatigue limit, long before the ram wears out the cast iron unit...
Show me an aluminum instrument that has any chance of lasting generations like many cast iron ones HAVE.

Wow! Good thing that high-end presses don't use aluminum