PI-WIKI-NED-10 · Precision Engineering · reviewed 2026-11-01
Needle Tip Geometry & Blunt Tip Physics Explained
Critical numbers
Standard Taper Range1.5 mm (ST) – 7.0 mm (ELT)
Apex Radius, Professional Grade< 12 μm
Apex Radius, Substandard> 25 μm
Surface Roughness (Ra)< 0.1 μm (electrolytic polish)
Taper Angle, Long Taper2.5°–3.5°
Taper Angle, Short Taper6°–10°
Dimensional Tolerance± 0.02 mm
Standard Piercing Gauges12g (2.05 mm) – 23g (0.57 mm)
Wall Thickness, 14g Piercing Needle0.30–0.35 mm
Optimal Ink Viscosity Range500–2,000 cP
Target DepthUpper-to-mid dermis (depth varies by body site)
Penetration ForceNo published figure for body art needles
Do not
- Using short-taper needles for fine-line detail work
- Ignoring gauge-to-jewelry mismatch for piercing
- Running high-viscosity ink at high speed
- Touching the needle tip
- Reusing a needle for a second client even with re-sterilization attempt
- Tattooing into dermis based on voltage alone without depth calibration
Applicable standards
- European Union — EU MDR 2017/745
- United States — FDA 21 CFR 880.5570
- ASEAN & Asia-Pacific — Thailand