Mach3 is for Milling. What do you mean Cold Saw?
I've found that Mach3 can be used to cut through most materials depending on what type of CNC machine you have.
Many on here have Plasma Cutting machines, which uses a high energy laser to cut with, and others use Milling Spindle Routers, which use
high carbide end mills of various sizes. Each of these are used to cut through steel, aluminum, brass, plastics, wood etc.
What material are you looking to cut?