Drill Angle
Drill Angle is the cone angle of the Säberg drill bit used to prepare a sample for layer-resolved coating thickness measurement with the Boring Thickness Module.
Definition
The Drill Angle is the full angle between the cone surface of the drill bit and the perpendicular to the coating surface. It is a physical property of the drill bit and is normally engraved on the bit by its manufacturer.
Why It Matters
The Boring Thickness Module converts the radial distance between adjacent ring boundaries (visible in the image of the drilled crater) into a layer thickness using:
Layer thickness [µm] = | r_outer − r_inner | × tan(Drill Angle) × mm/pixel × 1000
The calculated thickness is therefore directly proportional to tan(Drill Angle). Entering the wrong angle produces plausible-looking but incorrect µm values without any warning from the software.
Typical Values
| Drill Angle | Magnification factor (1 / tan) | Preferred for |
|---|---|---|
| 5.7° | × 10.04 | Thin coatings, layered systems with sub-50 µm layers |
| 10° | × 5.67 | General multi-layer paint systems |
| 20° | × 2.75 | Thicker industrial coatings |
| 30° | × 1.73 | Very thick coatings on small samples |
In Appearance Elements
- Parameter location: Boring Thickness module → properties panel → Drill Angle
- Default: 5.7°
- Allowed range: 0° – 90°
See also: Boring Thickness Parameters, Layer Depth, Total Depth.