Metal Drilling: The Ultimate FAQ Guide

Metal drilling is the process of using a drill bit to cut a circular hole or holes in metals.

In this guide, we shall cover topics that incorporate metal drilling.

For instance, we shall look at the drilling process, benefits, techniques, drill bits, and some limitations to metal drilling.

How Do You Drill Metal?

The first step before drilling metals is to have the right drilling tool and the right drill bits.

Here are the steps you should take when drilling metals:

Safety First

The process of drilling wood will generate sawdust.

Drilling through metal, on the other hand, produces sharp and small metallic fragments.

These shavings are dangerous to both your eyes and skin.

As a result, before you start drilling on metals, make sure you have the proper safety equipment.

Ensure you wear safety goggles and thick leather gloves when metal drilling.

Also, make sure you clamp the metal you are drilling.

This is because twisted drill bits can stick on the metal and if it stops halfway, its spinning force will transfer to the metal.

To prevent this hazardous situation, it is vital to clamp the metal.

Sacrificial Sandwich

This entails placing a flat piece of wood above and below the metal you are drilling.

Before drilling through the metal, you must first drill through the piece of wood.

If you are drilling through thin metal sheets, place a wooden sheet below the metal sheet then clamp the metal sheet.

The sacrificial sandwich will help you when making cleaner holes in the metals.

Pilot Hole

It may be tricky to drill through metals when dealing with drill bits.

For instance, the drill bits can go off track the moment you begin the drilling process.

This is why you need to make a dimple or pilot hole on the metal before drilling.

For instance, you can make a small indentation in the metal plate using a nail and hammer.

This little indentation aids in keeping the drill bit in place, permitting for a clean hole to be drilled through the metal plate.


Drilling metal sheets produces a lot of resistance, which creates heat.

The heat can damage the drill bits and the metal which you are drilling.

For this reason, you can minimize damage because of heat and friction by applying drops of oil to metal.

It is possible to use motor oil or household oil to reduce heat and friction during drilling.

Proceed Slowly

You need to take extra caution when conducting metal drilling.

For instance, the speed and pressure need to be low as most drills should operate at half the speed.

Some drills allow you to operate at low speeds and even maintain suitable pressure during the drilling process.

Stop When You See Smoke

When you see smoke during the metal drilling process, it means you are drilling too fast.

This high speed will produce more heat and friction.

It is therefore vital that you stop the drilling process immediately when you see smoke.

Afterward, you can allow cooling of the drill bit, then add some lubricant oil before beginning the drilling process.

Also, ensure you are drilling at low speeds.

Cleaning The Hole

You may see some jagged edges surrounding the opening following drilling.

To clean it, manually insert the drill bit in the hole to eliminate the metal shavings.

Drilling metal

Drilling metal

What Are The Common Metals To Drill?

There are several types of metals you can drill.

These include the following:

  • Copper
  • Aluminum
  • Stainless steel
  • Tin
  • Cast iron

Parts of drill bit

Parts of drill bit

How Do You Determine The Best Drill Bit For Metal Drilling?

A majority of drill bits can fit into cordless drills and standard corded drills.

Besides the drill bits looking alike, every type is unique when it comes to making holes in metals and they operate differently.

For instance, you can classify metal drill bits by the type of metal they drill through.

Some drill bits for metal drilling are suitable for drilling ferrous metals while others are suitable for drilling non-ferrous metals.

Here are some tips on how to determine the best drill bit for metal drilling:

Drill Bit Construction Material

A majority of drill bits are made with cobalt, carbide, or high-speed steel [HSS].

The drill bit material can affect its effectiveness during metal drilling.

  1. High-speed steel [HSS]

This is a multi-purpose drill bit that you can use when drilling ferrous, nonferrous, and carbon steel.

  1. Cobalt

This drill bit is only appropriate for drilling ferrous metals sheets and never for drilling nonferrous metals.

  1. Carbide

This drill bit material is suitable for use when drilling nonferrous metals such as tin and nonferrous metals.


Drill bits for metal drilling come with a black oxide or titanium coating.

The purpose of the coating is to minimize fiction which prevents heating and breaking of the drill bits.

Besides, the coating will increase the drill speed as it minimizes friction.

Shank Design

The shank is the side of the drill bit that will fit into the mandrel or chunk of the drill.

Shanks is not responsible for drilling but rather fit into the drill.

Ensure the size of the drill bit shank matches the chunk of the drill.

They come in sizes such as ½ or ¼ inches.

There are some shank designs suitable than others when it comes to drilling metals.

A majority of the shanks come as either hex or no-spin.

  1. Hex shank

This takes a shape similar to screwdriver bits.

Besides, this shank contains six sides that ensure the drill bit remains steady when drilling into metals.

  1. No-spin shank

This drill bit contains fluted shanks whose design ensures the bit does not slip during the metal drilling process.

What RPM Is Best For Metal Drilling?

The term RPM refers to the number of rotations per minute.

When a drill bit spins faster, it gets hotter quickly, therefore, it is ideal for the metal drilling process to proceed at slow speeds.

For hard metals such as steel and larger drill bits, the RPM needs to be slower.

When using small drill bits, you can perform the drilling process at about 3000 RPM.

Besides, when using larger drill bits, it is suitable for the RPM to be between 350 and 1000.

Why Is It Necessary To Use A Center Punch Tool In Drilling Metal?

This is a unique tool that you will use to form shallow dents on metal before drilling.

The operator will use the center punch tool to mark an area on the metal where you will drill using a drill bit.

Once it makes the punch, it will guide the drill bit to the suitable drilling area.

The drill bit may move off from the metal area when you do not use a center punch tool.

What Are The Most Common Metal Drilling Techniques?

These include the following:

Drilling metal

Drilling metal

Spot Drilling

The function of this technique is to make a hole that functions as a guide when drilling the final hole.

This means you will only drill partly on the metal as it guides the start of the next metal drilling process.

Center Drilling

This is a two-fluted tool that has twist drills with a countersink that is 60-degrees.

Also, you will use this process to drill countersink center holes on metals that you will mount between the center for grinding or turning.

Deep Hole Drilling

This technique entails drilling holes that are more than ten times greater than the diameter of the hole.

Micro Drilling

This entails drilling metal holes lower than 0.5 mm.

Vibration Drilling

This involves creating oscillations to feeding motion of drills to shavings can break up and are easily removable.

Circle Interpolating

This is a technique suitable for making holes using machine cutters.

What Are Metal Drilling’s Advantages?

Metal drilling will form minimal distortion as the process is precise.

Also, it is affordable to perform metal drilling than when using other processes.

Metal drilling can handle thick metal sheets.

What Are The Most Important Factors To Consider When Metal Drilling?

Ensure you have the correct drilling speed.

Clamp the metal and avoid applying excess pressure when drilling.

Where Is Metal Drilling Commonly Used?

Metal drilling happens in a variety of industries such as:

  • Construction industry
  • Medical machines
  • Electronic industry
  • Automotive industry

How Much Does Metal Drilling Cost?

There are different types of metal drilling in the market today.

For this reason, the price may go anywhere from 2000 US dollars.

What Is The Ideal Material Thickness To Consider For Metal Drilling?

Different drill bits can allow you to drill on metals of various thicknesses of even 3/8 inch.

What Are The General Practices To Observe In Metal Drilling?

These include the following:

  • Reading the user manual
  • Ensure you get proper training before conducting metal drilling

What Is The Best Lubricant To Use In Metal Drilling?

The lubricant you use depends on the task, size of the hole you are drilling, drilling speed, metal material, metal hardness, and metal thickness.

Some of the lubricants you can use during metal drilling include:

  • Motor oil
  • Machine oil
  • ATF
  • WD-40

What Is The Suitable Drill Bit Angle During Metal Drilling?

The common drill bit angles are 118 degrees and 135 degrees.

When conducting minor drilling, it is suitable to use drill bits whose angle is 118 degrees.

A 135-degree drill bit angle is suitable when drilling hardened metals.

What Is The Average Duration For Metal Drilling?

The time depends on several factors such as:

  • Drill bit material
  • Metal material
  • Revolutions per minute
  • Level of automation

What Are The Safety Precautions To Observe During Metal Drilling

Metal drilling machine

Metal drilling machine

These include the following:

  • Wear eye and ear protection
  • Put on safe clothing
  • Select the right drill bit
  • Ensure the start and stop buttons are easily reachable
  • Use brushes or vacuums to remove metal shavings
  • Clamp the metal before drilling to prevent it from spinning
  • Securely lock the drill bit within the chuck
  • When drilling, lubricate the drill bit.
  • Ensure the working area s clean
  • Make sure drill bits are sharp and clean
  • Shut off the power before connecting or removing the drill bit

What Are The Common Problems You Can Encounter In Metal Drilling?

Some of the common problems include the following:

  • Drill bit breaking
  • Slipping of the drill bit
  • Metal chips not breaking up
  • Damage to the point angle
  • Big holes
  • Rough holes
  • Drill bit blunting rapidly
  • Chips forming on lips of the drill bit
  • Wandering drill bits

What Alternatives Are There To Metal Drilling?

These include:

  • Hole punching
  • Notching
  • Trepanning

What Are The Most Common Metal Drilling Drawbacks?

The shape of the hole is limited since the drilling process is rotary, hence, can create circular holes only.

Drilling also generated heat and fiction which can be detrimental if not maintained.

For any questions of inquiry about metal drilling, contact us now.

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