What is a step drill/ step bit/ step drill bit?
A step drill , also known as stepped drill bit, step drill bit or step bit, is a conical drill bit with increasing diameters step by step. A step bit can be made of steel, high speed steel and cobalt or carbide tipped for drilling holes through soft materials like aluminum, plastics and wood,and hard materials such as bronze, cast iron and steel.
Sometimes, step drills will be coated by TiN (titanium-nitride) and TiAlN (titanium-aluminum-nitride) which makes it harder and more durable to offer a longer service life.