Pilot Holes

A pilot hole is a small hole drilled before the final hole size. Pilot holes improve accuracy and make larger holes easier to drill.

Why Use a Pilot Hole?

Pilot holes help:

• Keep the drill bit centered
• Reduce drill bit wandering
• Improve hole accuracy
• Reduce cutting force on larger drill bits
• Produce cleaner holes

When to Use Pilot Holes

Pilot holes are especially useful when:

• Drilling large holes
• Drilling thick material
• Working with precise hole locations
• Using step-up drill sizes

Small holes, such as rivet holes, often do not require a pilot hole.

Typical Process

1. Mark the hole location.
2. Center punch the hole.
3. Drill a small pilot hole (such as 1/8").
4. Drill the final hole size.

Best Practices

• Always center punch before drilling.
• Keep the drill perpendicular to the material.
• Use steady pressure and let the drill bit cut.
• Deburr the finished hole.

Key Idea

Pilot holes improve drilling accuracy and make larger holes easier to produce. Taking the extra step can prevent misplaced holes and improve part quality.