FASTENERS 101™

Drill Bit FAQ

Frequently Asked Questions (FAQ) About Drilling

Drilling FAQs

Quick answers to common questions about drilling and drill bits.

What are pilot holes?

Pilot holes are a pre-drilled hole for the screw or bolt to go into.

What are tapped holes?

Tapped holes are holes with threading cut into them with a specific kind of bit.

What is a countersunk hole?

A countersunk hole is a hole sunk down into the material so the head of the fastener sits flush or under the top material.

Do I need to drill into wood?

It is always a good idea to pre-drill into wood before driving a screw, it will prevent cracks and splitting in the wood.

How can I drill into concrete?

Using a hammer drill and a drill bit rated for masonry work.

What's the difference between a hammer drill and an impact drill?

A hammer drill can and usually should be used for drilling into a hard surface like brick or concrete. In contrast, an impact driver is used mainly for driving in fasteners like screws and nails.

Can I use spade bits on sheet metal?

No, spade bits are made for wood, using them in sheet metal will ruin the bit and result in an unclean hole.

What are wood drill bits?

What is a drill?

A drill is a tool that spins drill bits at high speeds to quickly and efficiently cut holes into different materials.

How do I drill a hole in drywall?

Using a hole saw.

What is a car reamer used for?

A car reamer is used to make an already existing hole bigger than the previous one.

What is drill bit lubricant for?

Drill bit lubricant is used on metal to keep a drill bit from generating too much heat, which can cause it to expand and snap inside of a hole.

How does a step drill work?

A step drill is commonly used when many different sized holes need to be drilled but carrying around a whole set of bits is inconvenient.

What size drill bit should I use?

The drill bit size depends on the fastener diameter and material. Use a bit slightly smaller than the screw or bolt shank for pilot holes, and check manufacturer recommendations.

How do I choose the right drill bit for metal?

Use a drill bit designed for metal and match the bit size, material and length to the application. High-speed steel (HSS) and cobalt drill bits are commonly used for metal drilling, while the appropriate length depends on the reach, rigidity and working clearance required.

Browse our Metal Drill Bits or learn more about the differences between jobber length and mechanic length drill bits .

Can I drill into tile without cracking it?

Yes, use a carbide-tipped masonry bit and a slow speed with light pressure, and consider a tile drill bit designed to prevent cracking.

What is the best drill for home use?

A cordless drill with variable speed and a hammer function (e.g., from brands like DeWalt or Makita) is versatile for home projects.

How do I prevent drill bit breakage?

Use the correct bit for the material, apply steady pressure, avoid overheating with lubricant, and ensure the drill is in good condition.

What is the difference between jobber length and mechanic length drill bits?

Jobber length drill bits have a standard general-purpose length that provides a balance of reach and rigidity for everyday drilling. Mechanic length drill bits are shorter, which provides increased rigidity, reduced flex and easier access in confined drilling locations.

Compare Jobber Length Drill Bits and Mechanic Length Drill Bits , or read our complete Jobber vs. Mechanic Length Drill Bit Guide .