This is the disk styli #A-5000-3613.
These styli are ‘sections’ of highly spherical balls and are available in various diameters and thicknesses. Disc styli are designed to inspect undercuts and grooves within bores which may be inaccessible to star styli. A range of disc styli offers a radius end roller to enable groove width measurement. Silver steel tips are heat treated and precision ground to a high tolerance.
| Thread mount (DG) | M2 |
| Disk Depth (B) | 2.3 mm |
| Roller Depth (L) | 3.0 mm |
| Stem diameter (DS) | N/A |
| Disk diameter (DK) | 18.0 mm |
| Disk material | Silver Steel |
| Stem material | Stainless Steel |
| Mass | 2.7 g |
