Understand the key differences between twist drills and carbide drills, their advantages, applications, and how to select the right drill bit for your machining requirements.
A twist drill is one of the most widely used types of drill bits. It gets its name from the helical flutes that spiral around the body of the drill. These flutes help remove chips from the hole while the cutting edges at the tip perform the drilling operation.
Twist drills are commonly manufactured from high-speed steel (HSS), cobalt alloys, or other tool steels. HSS twist drills are particularly popular because they offer a good balance between hardness, toughness, performance, and cost.
They are available in a wide range of sizes and are suitable for general-purpose drilling.
Affordable purchase price makes them ideal for budget-conscious shops
Excellent resistance to breakage and vibration tolerance
Suitable for a wide range of materials
Can be resharpened and reconditioned multiple times
Available in many sizes and geometries
Suitable for hand drills, drill presses, and CNC machines
Twist drills are commonly used for drilling:
For general-purpose drilling, an HSS twist drill is often a practical and economical choice.
A carbide drill is a drill made with a cutting body or cutting edges containing cemented carbide, a very hard tool material typically based on tungsten carbide.
Carbide is significantly harder and more wear-resistant than conventional HSS. This allows carbide drills to operate at higher cutting speeds and maintain their cutting edge for longer when used under appropriate conditions.
Carbide drills are particularly valuable in CNC machining and high-production manufacturing, where drilling accuracy, productivity, and tool life are important.
Maintains cutting edge far longer than HSS
Superior cutting performance on hard materials
Can operate at significantly faster speeds
Precise hole-making capabilities
Ideal for demanding production applications
Performs well on hard and abrasive materials
Carbide drills are frequently used for:
| Feature | Twist Drill | Carbide Drill |
|---|---|---|
| Typical Material | HSS, cobalt, tool steel | Cemented carbide |
| Hardness | Good | Excellent |
| Toughness | Higher | Lower |
| Wear Resistance | Good | Very High |
| Cutting Speed | Moderate | High |
| Tool Life | Good for general use | Excellent under suitable conditions |
| Cost | Lower | Higher |
| Shock Resistance | Better | More Brittle |
| Sharpening | Relatively Easy | More Specialized |
| Best Suited For | General-purpose drilling | Precision & high-production machining |
The answer depends on what you mean by durability.
A carbide drill generally offers greater wear resistance and can maintain its cutting performance for a long time under stable machining conditions. This makes it highly effective for production environments.
A twist drill, particularly an HSS drill, is generally tougher and more forgiving. It is better able to tolerate vibration, minor misalignment, and less-than-ideal working conditions.
Therefore, carbide usually wins in terms of wear life, while HSS twist drills often have an advantage in toughness.
For occasional drilling and general workshop use, twist drills are usually more economical. They cost less initially and can often be resharpened multiple times.
Carbide drills have a higher upfront cost, but they can become more economical in high-volume production because of their higher cutting speeds, productivity, and potential tool life.
The best choice should therefore be based on cost per hole, rather than simply the purchase price of the drill.
For maintenance work, workshops, fabrication, and general engineering, HSS twist drills remain extremely useful.
Carbide drills are particularly effective when the machine, workholding, coolant system, and cutting parameters are properly matched to the tool.
There is no universal winner.
Twist drills are the better all-around choice when versatility, toughness, affordability, and ease of sharpening are the priorities.
Carbide drills are the better choice when high productivity, wear resistance, precision, and demanding machining conditions justify the additional cost.
Choose HSS twist drills for versatility and value.
Choose carbide drills for speed, precision, and production performance.
Selecting between a twist drill and a carbide drill comes down to the material being drilled, machine capability, production volume, required hole quality, cutting conditions, and budget.
For everyday drilling, a good-quality HSS twist drill can provide excellent performance at a reasonable cost. For high-speed CNC machining and demanding applications, carbide drills can deliver significantly higher productivity and wear resistance.
Rather than choosing a drill based solely on its material or price, consider the complete machining application. The right combination of drill geometry, material grade, cutting speed, feed rate, coolant, and machine stability will ultimately determine drilling performance.
The right drill is not necessarily the hardest or most expensive one—it is the one that best matches the job.
Expert machining and drilling specialists
We provide comprehensive guides, technical comparisons, and industry insights to help machining professionals make informed decisions about cutting tools and drilling equipment.
General drilling, versatility, affordability
High production, CNC, hard materials
Calculate cost per hole, not purchase price