Which drill bit for which diameter?
Choosing the right drill bit is crucial for precise and clean machining results. When tapping threads in particular, the drill diameter must match the desired thread exactly. This is the only way to produce stable, precisely fitting connections and minimize tool wear.
As a general rule, the drill diameter (core hole) is always slightly smaller than the subsequent thread. A proven rule of thumb is:
Drill diameter = thread diameter – pitch
With high-quality precision tools – such as those available at Nachreiner Tools – you can achieve optimum results with a wide variety of materials such as steel, aluminum or plastic.
Pre-drilling table for metric threads
| Thread | Pitch | Core drill |
|---|---|---|
| M3 | 0.5 mm | 2.5 mm |
| M4 | 0.7 mm | 3.3 mm |
| M5 | 0.8 mm | 4.2 mm |
| M6 | 1.0 mm | 5.0 mm |
| M8 | 1.25 mm | 6.8 mm |
| M10 | 1.5 mm | 8.5 mm |
| M12 | 1.75 mm | 10.2 mm |
Tip: For particularly hard materials, a slightly adapted bore is recommended for better tool life.
Which drill bit for which material?
In addition to the diameter, the material also plays a major role:
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Steel: HSS or VHM drills for high load capacity
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Stainless steel: special coated drills with high heat resistance
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Aluminum: sharp cutting edges for clean chip removal
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Plastic: Drill bit with optimized geometry to prevent tearing
Nachreiner Tools offers the right precision drill bit for every application.
❓ FAQ – Frequently asked questions
Which drill bit do I need for an M6 thread?
For an M6 thread, you need a 5.0 mm drill bit.
What happens if I drill too big a hole?
The thread is not cut correctly and holds less well or, in the worst case, not at all.
Where can I find suitable drill bits?
You can find a large selection of high-quality drilling tools for precise applications here:
👉 Nachreiner tools
What is the difference between HSS and HSSE drills?
HSS (High Speed Steel) drill bits are standard drill bits for general applications such as steel, aluminum or plastic and are impressively versatile.
HSSE drill bits also contain cobalt. This makes them significantly more heat-resistant and wear-resistant – ideal for demanding materials such as stainless steel.
Contact us for more information!
Do you have any questions or would you like to request a quote? Our team is always at your disposal. Contact us now.
