Carbide Drills Break Easily ｜ Causes and Solutions

Carbide drills deliver high-speed cutting and wear resistance, but their brittleness makes them prone to breakage. This article explains the main causes of premature failure and practical solutions to extend tool life in industrial machining.
■ Strength Comes With Brittleness: The Weakness of Carbide Drills
Carbide drills are widely used in CNC machining and metal cutting thanks to their hardness, durability, and ability to cut at high speeds.
But carbide is inherently brittle. Many breakages are caused not by poor tool quality but by:
・ Incorrect cutting parameters
・ Improper cooling
・ Tool selection errors
・ Poor clamping and vibration
Understanding these causes is the first step to preventing tool failure.
■ Main Causes of Carbide Drill Breakage
1. Vibration
・ Poor clamping of drill or workpiece
・ Excessive drill overhang
・ No support at the drill tip
> Even minor vibrations can cause tip chipping in brittle carbide.
2. Improper Cutting Parameters
・ Feed rate too high at low RPM
・ Drilling at an inclined entry angle
・ Dry drilling without coolant
> Creates unstable loads, leading to cracks.
3. Heat Accumulation
・ No through-coolant system
・ Inadequate cutting oil for difficult materials
> Excess heat accelerates carbide degradation.
4. Workpiece Geometry Issues
・ Drilling near edges or close to an existing hole
・ Breakthrough drilling without support
> Causes lateral shear stress, leading to breakage.
5. Wrong Drill Selection
・ Using aluminum-specific drills on stainless steel
・ Incorrect coating (e.g., TiN on hard alloys)
> Results in rapid wear and sudden failure.
■ How to Prevent Carbide Drill Breakage
・ Optimize cutting parameters
Follow manufacturer recommendations; fine-tune RPM & feed for each material.
・ Use proper cooling systems
Prefer through-coolant drills; avoid dry drilling.
・ Ensure rigid clamping
Check runout, tool holder rigidity, and minimize overhang.
・ Select the right drill
Choose carbide grade, coating, and flute design suited for material and chip type.
■ Recommended Product: DVAS Carbide Drill Series ｜ MMC Hardmetal (Thailand) Co., Ltd.
For manufacturers facing drill breakage issues, we recommend the DVAS Solid Carbide Drill Series by MMC Hardmetal (Thailand) Co., Ltd.
■ Key Features of DVAS Series
・ High precision: Advanced edge & flute geometry for accuracy-critical applications
・ Wear resistance: State-of-the-art coating improves tool life, prevents chipping
・ High performance: Suitable for steel, cast iron, stainless steel, and alloys
・ Stable machining: Reduces tool changes, improving productivity
・ Through-coolant compatible: Ideal for CNC machining with high efficiency
With its durability and versatility, DVAS is the right solution for factories aiming to reduce waste, extend tool life, and achieve consistent quality.
■ Full details can be downloaded from the PDF. For further inquiries, please contact us.
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