06 Tips to Select the Right Drill Bit – Step By Step Guide!

The drill is a widely used tool both domestic as well as industrial. There are types of drills are available for many purposes. If you need to use a drill bit, you must know about drilling material, drill bit material, drilling speed, types of the drill bit, and many more. I will guide you to select the best drill bit for your project.

When you select a drill bit, you must consider so many factors. Those factors are directly affecting the drilling purpose. So it is time to choose the best drill bit for your task among thousand of drill bits. So let’s keep reading on.

When you select the drill bit, you should consider the main 03 things of the drill bits.

Material – This is meant by the manufactured material of the drill bit.
Coatings – Some drill bits are coated with different materials. Before you select, check whether those are alright for you.
Geometry – Geometry is the drill bit angle. This is the cutting angle.

If you know these 03 things, you can select the drill bit easily. So let’s see what these are and how they affect the drilling process.

Tip 01 – Drill Bit Material Should Harder Than Workpiece

Drill bits are made with different materials
Drill bits with manufactured materials

When you select the drill bit, you must know about the drill bit manufactured material. There are so many materials used to manufacture the drill bits. All are for the specified works. So let’s see what they are and their usage.

Drill bits that are manufactured using these materials can be used in hammer drills, combi drills, SDS plus, SDS max, and many more. We should consider the drill bit material when we select that.

High-Speed Steel

High-speed steel is the most using drill material, and it is with;

  • Least expensive
  • Use in press drills and hand drilling
  • Easy to resharpen
  • Mostly use in wood

High-Speed Steel with Cobolt Added

This is more strength than HSS. It is made by adding cobalt to the high-speed steel. Those are;

  • Easy to resharpen
  • More heat and wear resistance
  • better than HSS
  • One sharpen can cut 100 holes

Carbide Drill Bits

This is the most expensive drill material. There are full carbide drill bits as well as carbide drill bit tips.

  • Sharpness is durable
  • More expensive
  • heat and chip resistance
  • One sharpen can cut 1000 holes
  • The cost per hole is low

Drill Bits and Suitable Projects

Low Carbon Steel – Suitable for softwood

High Carbon Steel – Used both wood and metal

High-Speed Steel Drill Bits– These bits can be used to drill metal, or hardwood. Materials that are not able to be cut using the high carbon steel HSS is used.

High-speed Steel with Cobolt – Drill stainless steel and more drilling strength than HSS

Carbide Drill Bits Used for stone, Bricks, concrete, metals, woods

Polycrystalline Diamond Drill bits – These are used to drill tiles, stones, and glasses.

Tip 02 – Durable and Resistance Drill Bits Are Outer Coated

The outer coating is used to add more strength and more resistance, durability, friction reduction and increase lifetime. These coatings are used with specific materials relevant to specific tasks.

Drill bit outer coating reduce resistance
Coatings applied on drill bits Image Source.

By applying the outer coating layer, its strength and efficiency can be increased. There are so many coatings drill bits are available. It can be named by its outer visualization, and it will be easy to recognize you.

Regular (Bright Finish)

  • This is the most used drill bit.
  • Made with low carbon steel and aluminium
  • Very Cheap

Black Oxide

  • More lubricity than a bright finish
  • Resistance to oxidation
  • Additional heat treatment

Titanium Nitride (TiN)

This is a common coating and a great entry-level for drilling. It is with high heat transfer.

Titanium Carbo Nitride (TiCN)

  • High performance
  • Harder and wearing

Titanium Aluminium Nitride (TiAlN)

  • Higher performing
  • Good for steel
  • high temperature
  • Suitable for stainless steel
  • Not good for aluminium

More than material and coatings, there should be a cutting angle for the drill bit.

Tip 04 – More Drilling Depth Required Longer Flute

Drill bit flute helps to efficiency drilling
Parts of the drill bit

The flute is the twisty path of the drill bit. The flute is the way to evacuate the chips to outside.

There are different lengths of drill bits. Those drills are with different flutes length. You should need proper fluted length for removing the cutting chips. Else Drill can be overheated. According to the length of drill bit, those are named as

Stub – Short drill bits (Use for CNC machines)
Jobber – Long drill bits (Use for hand drill)

Read More About – How to Identify the Drill Bits? – Expert Guide!

How Much Flute Length Does It Need to Drill the Hole?

You should have two times the drill diameter in flute length above the hole when you are drilling. This will ease the evacuation of the chips inside. It will stop the compaction of the chips inside.

Tip 05 – Cutting Angle Should Compatible With Material

Drilling is the process of cutting and removing the material. When the tip of the drill bit is cut, the material and comes out through the flutes. If there is no proper cutting angle, the drill bit can be heated, and then it can break. Chips also will not come out if there is no proper cutting angle.

There are two main cutting angles for the drill bits. Those are 118° and 135°

118°

  • This is suitable for stub length
  • Used for mild steel aluminium
  • Soft metals

135°

  • This is suitable for jobber length
  • Hard steel
  • Tougher materials

Tip 06 – Drill Bit Should Have Enough Helix Angle

This is another thing that you should know about the drill bits. The helix angle is the flute angle. When the flute angle;

30° – Regular usage (most materials)
Less than 30° – Harder steel such as aluminium alloys
More than 30° – Stainless materials

What is Pilot Hole?

A pilot hole is a small diameter drilled hole with 1.5 times drilling diameter depth into the material when drilling depth is more than eight times (8X) of the drill bit diameter. Using a pilot hole will not slip the drill bit here and there, and easy to start drilling by using more diameter drill bits.

Read More About – Ultimate Pilot Hole Guide – Method | Depth | Drillbit Size

When Should I Sharpen my Drill Bit?

You should sharpen your drill bit when the chippings are below 0.02″ (0.50mm). If you don’t sharpen on time drill bit will overheat due to the friction with the material. So using the proper method, you should sharpen your drill bit on time.

Read More About – Sharpening Drill Bits – (Twist-Spade-Brad-Spur-Forstner)

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