WARNING: Machine tools present a safety hazard. Improper operation can result in severe injury. These topics are for non-laboratory study only and are not to be used in conjunction with the operation of any tool or machine described herein. Never use a machine tool without the supervision of a qualified instructor.
Generally speaking metals are not brittle when compared to a rock or other materials (Zinc is an exception). Metals do not break easily because of their metallic bonds. However if improperly heat treated a steel can become relatively brittle and crack. Pig iron is also more brittle than any other form of iron or steel