What size drill bit for pinning?

Use a drill bit that matches your pin diameter. For 0.8mm brass rod, use a 0.8mm bit. For 1.0mm piano wire, use a 1.0mm bit. A slightly larger bit (0.1mm oversize) makes insertion easier but gives a weaker joint — fill any gap with CA glue.

What drill bits do I need for model making?

A basic set covers 0.3mm to 2.0mm in 0.1mm increments. The most commonly used sizes are 0.5mm (fine detail), 0.8mm (pinning), and 1.0mm (larger pins). Buy quality HSS bits — cheap ones snap easily at small diameters.

Should I use a pin vise or power drill?

A pin vise (hand drill) is essential for model work. It gives you precise control and prevents breaking small bits. Power drills spin too fast and can crack plastic. Use a pin vise with double-ended collets to hold any bit from 0.1mm to 3.0mm.

How do I prevent drill bits from snapping?

Keep the bit perpendicular to the surface. Let the bit do the work — do not press hard. Clear swarf frequently by withdrawing the bit. Start with a smaller pilot hole for larger sizes. Replace blunt bits — they need more pressure and are more likely to snap.

ModelCalcs

Drill Bit Size Calculator — Precision Holes

Find the right drill bit size for pinning, rivet holes and detail work at scale.

Purpose

Pin Material Diameter (mm)

How We Calculate This

Matches drill bit size to your purpose — pinning, scale holes or detail work — and recommends the nearest standard bit.

Logic

Pinning: Bit size = Pin material diameter
Scale holes: Bit size = Real hole diameter / Scale ratio
Nearest bit from standard set: 0.3 to 3.0mm

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.