Step drill

A step drill (or step drill bit) is a specialized cutting tool used to drill holes of multiple diameters in a single operation. Instead of having a single cutting diameter like a standard drill bit, a step drill has a series of increasing diameters along its length, forming a “staircase” or “stepped” profile.

Key Features of a Step Drill:

• Multiple Diameters: Each “step” is a cutting diameter, allowing you to drill several hole sizes without changing bits.

• Conical Shape: Most step drills taper gradually, with each step having a flat cutting area.

• Self-Centering Tip: Usually has a pointed or pilot tip for easy centering.

• Materials: Often made of HSS (High-Speed Steel) or carbide, sometimes coated with TiN or TiAlN for longer life.

Common Applications:

Application Details

Sheet Metal Drilling Great for thin materials like aluminum, steel, plastics

Electrical & HVAC Installations Used to create holes for conduits or switches

Deburring & Chamfering Can clean or bevel hole edges

Panel Mounting Drills clean holes for instruments, buttons, etc.

Advantages:

• Fewer tool changes

• Clean holes in thin materials

• Precise, concentric steps

• Deburring as you drill

Limitations:

• Not suitable for thick materials (typically under 5mm)

• Limited to the step sizes designed on the tool

• Not ideal for hard or abrasive materials unless made from carbide