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Differences and Applications of Cobalt Drill Bits vs. Carbide Drill Bits
time：
2026-04-21 08:40
source：
Lizhou
cobalt vs carbide drill bits Cobalt Drill Bits and Carbide Drill Bits
Table of Contents:
- What is a cobalt drill bit?
- What is a carbide drill bit?
- What is the difference between cobalt drill bits and carbide drill bits?
- Comparison between cobalt drill bits and carbide drill bits?
- What materials are cobalt drill bits and carbide drill bits used to machine?
- Common problems with carbide drill bits?
I. What is a cobalt drill bit?
A cobalt drill bit is a high-speed steel drill bit to which the metal “cobalt” has been added; its full name is HSS-Co Cobalt-containing high-speed steel drill bits—ordinary high-speed steel bits are not hard enough and lack heat resistance, so they easily become soft and dull when drilling stainless steel. However, by adding 5%-8% After cobalt is added, the drill bit’s high-temperature resistance and wear resistance are significantly enhanced, making it particularly suitable for drilling difficult-to-machine metals such as stainless steel, iron, and alloy steel.
II. What is a cemented carbide drill bit?
Carbide drill bits are drills made entirely from cemented carbide (tungsten steel), also known as solid carbide drill bits or tungsten steel drill bits. They are not made of steel; instead, they are composed primarily of tungsten carbide ( Restroom ) A superhard composite material made by sintering powdered raw materials with cobalt under high temperature and high pressure, which exhibits higher hardness than cobalt-tungsten carbide bits and high-speed steel.
III. What is the difference between cobalt drill bits and carbide drill bits?
1. Different materials
Cobalt drill bits are made of high-speed steel. HSS-Co, Cobalt is added to the steel, but it is still essentially steel.
Carbide drill bits are made by sintering tungsten carbide, which is a superhard material, not steel.
2. Hardness and lifespan are different
Cobalt drill bits have moderate hardness, average wear resistance, and a typical service life.
Carbide drill bits have extremely high hardness and exceptional wear resistance, with a service life that is **[blank]** times that of cobalt drill bits. 5-20 times
3. Different heat resistance
Cobalt drill bits have excellent heat resistance, making them ideal for drilling materials that tend to generate significant heat, such as stainless steel.
Carbide drill bits soften easily at high temperatures, enabling high-speed cutting.
4. Different toughness
Cobalt drill bits have excellent toughness, are impact-resistant, and are unlikely to break—making them suitable for use with hand drills as well.
Carbide drill bits are relatively brittle, sensitive to vibration and deflection, and best suited for machine tools with high rigidity.
IV. Comparison between Cobalt Drill Bits and Carbide Drill Bits?
Next, let’s compare the differences between cobalt drill bits and carbide drill bits by organizing them in a table. ~
| Cobalt drill bit | Carbide drill bit |
Hardness | HRC62-68 | HRC80-82 (Higher than cobalt) |
Resilience / Impact resistance | Capable of withstanding full-load, side-loading, and continuous breakage. | Brittle, impact-sensitive, and prone to chipping. |
Red hardness | 600 Maintain hardness at around ℃ | 800 degrees Celsius + Remains stable; does not soften under high-temperature cutting. |
Processing speed | Medium speed | Capable of high-speed cutting ( CNC Scene) |
Wear-resistant | Better, superior to the ordinary HSS | Extremely strong, with a lifespan comparable to that of a cobalt drill bit. |
V. What materials are cobalt drill bits and carbide drill bits used to machine?
Cobalt drill bit ( HSS-Co Cobalt-tipped drill bits are suitable for machining: stainless steel, carbon steel, alloy steel, die steel, cast iron, and more.
Characteristics of cobalt drill bits: excellent toughness and impact resistance; suitable for hand drills and conventional machine tools; low requirements for machine rigidity.
Carbide drill bits are suitable for machining quenched steel, tempered steel, high-hardness steels, stainless steel, alloy steels, cast iron, aluminum alloys, copper alloys, and more.
Characteristics of cemented carbide drill bits: extremely high hardness, excellent wear resistance, and long service life, making them suitable for CNC , high-speed, high-precision drilling with CNC equipment.
VI. Common Issues with Carbide Drill Bits?
Q1: Why are carbide drill bits prone to breakage?
Answer: The primary reason is that the equipment’s design rotational speed is not optimal; excessive vibration can also cause tool breakage, and uneven cutting forces can easily lead to chipping or fracture of the cutting edge.
Q2: Can carbide drill bits be ground?
Answer: It can be ground, but only with a diamond grinding wheel; a regular grinding wheel won’t work.
Q3: Can carbide drill bits be used with a hand drill?
Answer: Not recommended. Hand drills generate significant vibration and have unstable rotational speed, making blade breakage very likely.
Q4: Which is better for machining stainless steel: a carbide drill bit or a cobalt drill bit?
Answer: For small-batch production, cobalt-tipped drills can be used; for large-batch production, high-speed machining is recommended, and carbide drills should be used to achieve high hole accuracy and long tool life.
Q5: What is the typical service life of a carbide drill bit?
Answer: Under normal operating conditions, the service life is that of a standard cobalt drill bit. 5-20 The multiple depends on the workpiece material and cutting parameters.
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