Difference between mild steel and chromoly?

Whats the difference between mild steel and chromoly, say with a K-member for example. I would assume chromoly is stronger, but if so, how much stronger and how do weights compare? Thanks.

Ken R.

Generally, chrome moly is used to reduce weight. Because its stronger, you can use a thinner wall section in the tubing, reducing the weight, while keeping the strength the same. But chrome moly is difficult to weld correctly.

Thanks for the info.

Ken R.