Carbide vs Titanium Drill Bits: Which Should You Use?

Carbide vs titanium drill bits is not quite a comparison between two equivalent tool materials.

A carbide drill is normally manufactured from cemented tungsten carbide, whereas a drill sold as a “titanium drill bit” is usually a steel drill — commonly high-speed steel (HSS) — with a thin titanium-based coating applied to its surface.

The difference matters because the underlying tool materials have very different properties.

Solid carbide provides excellent hardness, rigidity and wear resistance, making it particularly suitable for controlled machine drilling and demanding production applications. A titanium-coated HSS drill is generally tougher and more tolerant of shock, making it useful for general-purpose and portable drilling.

The best choice therefore depends on the material being drilled, the machine, hole requirements and production conditions.

Are Titanium Drill Bits Made from Titanium?

Usually, no.

The term “titanium drill bit” commonly refers to a steel drill that has been coated with a titanium-based compound.

The coating is extremely thin and is intended to improve characteristics such as:

• wear resistance
• friction
• heat resistance
• tool life
• cutting performance

The main body of the drill still provides most of the tool’s strength and toughness.

This is different from a solid carbide drill, where the tool itself is predominantly manufactured from cemented tungsten carbide.

It is therefore more accurate to compare:

solid carbide drill

with

titanium-coated HSS drill

rather than treating carbide and titanium as two equivalent bulk materials.

What Is a Solid Carbide Drill?

Solid carbide drills are manufactured from cemented tungsten carbide.

Very hard tungsten-carbide grains are combined with a metallic binder, commonly cobalt, to produce a dense cutting-tool material with excellent hardness and abrasive wear resistance.  For a broader explanation of the material itself, see our What Is Carbide? guide.

This gives solid carbide several important advantages:

• high rigidity
• excellent wear resistance
• ability to retain a sharp cutting edge
• suitability for high cutting speeds
• good dimensional stability
• long tool life under the correct conditions

The trade-off is toughness.

Carbide is less tolerant of bending, impact and vibration than HSS. Excessive runout, poor workholding or an unstable machine can therefore cause a carbide drill to chip or fracture.

This is one reason solid carbide performs particularly well on CNC machines and other rigid machining systems.

What Is a Titanium-Coated Drill?

A titanium-coated drill normally starts as an HSS or related tool-steel drill.

A hard coating is then deposited onto its surface.

The coating does not transform the underlying steel into carbide. Instead, it improves the surface characteristics of the cutting edge while retaining much of the toughness of the HSS body.

This can provide a useful balance for general drilling applications.

Common Titanium-Based Coatings

Several coatings are commonly referred to as titanium coatings.

Titanium Nitride – TiN

TiN is probably the most recognisable coating because of its gold appearance.

It is a general-purpose hard coating used to improve wear resistance and reduce friction compared with an equivalent uncoated tool.

TiN-coated HSS drills are widely used for general machining and drilling applications.

Titanium Carbonitride – TiCN

TiCN is generally harder than TiN and usually has a grey to violet appearance.

It can provide improved wear resistance in suitable steel applications.

It should not automatically be considered a coating for aluminium and other non-ferrous materials, because coating choice depends strongly on the workpiece and machining conditions.

Titanium Aluminium Nitride – TiAlN

TiAlN is generally darker, often appearing black-violet.

It has good performance at elevated cutting temperatures and is widely used on tooling intended for more demanding machining applications.

Different manufacturers use a wide range of coating formulations, so the colour of a drill should not be used as the only method of identifying either its coating or underlying tool material.

Coating specialists such as Ionbond offer titanium-based coatings including TiN, TiCN and TiAlN for cutting-tool applications, with the choice depending on the tool material and machining conditions.

Which Is Harder?

Solid carbide is substantially harder and more wear resistant than conventional HSS.

This is one of its main advantages for production machining.

A titanium coating improves the surface of an HSS drill, but the underlying tool remains HSS. Once the coating at the cutting edge becomes worn away or is removed during sharpening, the exposed material behaves according to the properties of the base steel.

With a solid carbide drill, the carbide material extends throughout the cutting portion of the tool.

OSG, for example, describes micrograin carbide drills as providing superior hardness and wear resistance compared with HSS.

Which Is Tougher?

HSS is generally tougher and more tolerant of impact and bending.

This makes titanium-coated HSS drills particularly useful where the drilling system is less rigid. For a fuller comparison of the two cutting-tool materials, see our Carbide vs High-Speed Steel (HSS) guide.

Examples can include:

• hand-held drilling
• portable drilling equipment
• less rigid machines
• applications where accidental side loading is possible
• maintenance and general workshop work

A solid carbide drill requires better control.

Its high rigidity is an advantage during machining, but that same characteristic makes it less forgiving if the drill is subjected to sideways movement or excessive vibration.

Which Is Better for CNC Machining?

For suitable production applications, solid carbide is normally the more capable cutting-tool material.

A rigid CNC machining centre allows the advantages of carbide to be used properly.

These can include:

• higher cutting speeds
• improved hole accuracy
• greater wear resistance
• consistent diameter
• longer production runs
• better repeatability

Modern solid carbide drills may also incorporate internal coolant, specialised point geometries and coatings designed around particular workpiece materials.

Sandvik specifically identifies runout control as an important factor in successful solid-carbide drilling because it affects process security, tool life, hole quality and surface finish.

For production drilling, the question is therefore not simply whether carbide is harder. Machine rigidity, runout, coolant, cutting conditions and drill geometry all matter.

Which Is Better for a Hand Drill?

For most ordinary hand-held drilling, an HSS-based drill is generally the more practical choice.

A hand drill cannot control alignment and tool loading as accurately as a rigid machining centre.

The toughness of HSS means it can tolerate a degree of bending or shock that could damage a brittle solid-carbide drill.

That does not mean carbide is inferior. It simply means its advantages are best used in the right environment.

Which Lasts Longer?

Under suitable machining conditions, solid carbide can provide substantially greater wear resistance than HSS.

However, tool life depends on much more than material.

Important factors include:

• workpiece material
• cutting speed
• feed
• hole depth
• coolant
• runout
• drill geometry
• coating
• machine rigidity
• workholding

A carbide drill used incorrectly may fail much sooner than a well-selected HSS drill.

Likewise, a titanium coating can increase the useful life of an HSS drill, but the benefit depends on both the coating and application.

Which Gives the Better Hole?

Again, the application matters.

On a rigid CNC machine, a correctly selected solid carbide drill can provide excellent:

• diameter consistency
• positional accuracy
• surface finish
• straightness
• repeatability

Its greater rigidity reduces tool deflection.

For less controlled applications, the extra toughness of HSS may be more valuable than maximum rigidity.

What Materials Can Solid Carbide Drills Machine?

Appropriate solid carbide drills are available for a very broad range of materials including:

• steels
• stainless steels
• cast iron
• aluminium
• non-ferrous metals
• titanium alloys
• nickel-based alloys
• hardened materials

However, one carbide drill is not automatically suitable for all of them.

Grade, point geometry, flute design and coating need to be selected around the workpiece material.

For example, Guhring offers carbide drills with TiAlN coatings for steel, stainless steel and cast iron, with particular ranges also suitable for non-ferrous and difficult-to-machine alloys.

Can Titanium-Coated Drill Bits Be Sharpened?

Yes, an HSS drill can normally be resharpened if sufficient material remains and the drill is otherwise serviceable.

However, sharpening removes material from the cutting edge and therefore also removes the original coating from the reground area unless the tool is subsequently recoated.

This doesn’t necessarily make resharpening uneconomical, but it is worth understanding that a sharpened coated drill will not automatically retain the exact surface condition it had when new.

Can Carbide Drills Be Sharpened?

Yes.

Solid carbide drills can often be professionally reground, subject to the condition and geometry of the tool.

Accurate sharpening is particularly important because features such as:

• point geometry
• clearance
• cutting-edge preparation
• concentricity
• flute relationship
• coolant-hole position

can all influence drill performance.

Modern solid-carbide drilling tools are specifically designed with regrinding in mind in many industrial applications. Sandvik, for example, describes its current solid-carbide drill geometry as readily reground to extend useful tool life.

Carbide vs Titanium Drill Bits – Quick Comparison

Which Drill Should You Choose?

Choose the tool around the application rather than simply buying the hardest drill available.

A titanium-coated HSS drill can be a good choice where toughness, flexibility and general-purpose use are more important than maximum wear resistance.

A solid carbide drill is generally more appropriate where the machine is rigid and the application requires high accuracy, high productivity, longer tool life or reliable production performance.

For demanding CNC applications, the exact carbide grade, geometry, coating and coolant arrangement can be just as important as the fact that the drill is carbide.

Need Help Choosing a Drill?

Prima Tooling supplies and manufactures drilling tools for engineering, woodworking and production-machining applications.

Our range includes solid carbide drills, TCT drilling tools and bespoke drilling solutions, together with tooling for applications where standard catalogue products do not provide the required size, geometry or performance.

If you need help selecting a drill, send us the:

• material being machined
• hole diameter
• hole depth
• machine type
• spindle speed and feed if known
• coolant arrangement
• existing drill or part number

and we can advise on suitable tooling.