[L78toLT1]

Originally Posted by L78toLT1

Gray cast iron is much better at absorbing the energy from vibration due to the flake like microstructure. High nodular iron is not as good at dampening vibration, but is much stronger. In steels, higher strength correlates with decreased dampening properties. The next time you're up to your elbows in a motor to the point where the crank is removed, rap on one of the counterweight with something metallic. If it's steel you will be rewarded with a sustained, high frequency ringing. If it's cast, all you'll get is a dull thud

This was in response to CMitchell's comment on cast iron. I forgot to quote the applicable section of his post.