TABLE 1. Hardness, shape and some of the particle sizes available for the most popular airbrasive powders.
| Air-abrasive Powder | Hardness (Mohs) |
Shape | Available Particle Size (μm) |
| Aluminium oxide | 9 | Blocky and sharp | 10-150 |
| Silicon carbide | 9 | Blocky and sharp | 20-50 |
| Glass beads | 6 | Spherical | 35-100 |
| Crushed glass | 5-6 | Blocky and sharp | 50-75 |
| Pumice | 6 | Blocky and sharp | 75 |
| Dolomite | 3.5-4 | Blocky | 150 |
| Plastic | 2-4 | Blocky | 50-200 |
| Walnut shell | 3-4 | Blocky | 250 |
| Sodium bicarbonate | 3-4 | Monoclinic | 50-100 |
| Wheat starch | 2 | Lenticular and spherical | 100 |
TABLE 2. Elements incorporated into blast cabinets. * Of the remainder (66.7%) who responded negatively, 58.7% said they wore protective gloves.
| Element/Equipment | % Responders |
| Dust Extraction/venting | 98.3 |
| Integral lighting | 84.5 |
| Magnifying lens | 60 |
| Integral gauntlets | 33.3 * |
TABLE 3. The results of the trench scatter tests.
| Powder | Angle | Working distance (mm) |
Scatter width (mm) |
Scatter length (mm) |
Trench depth (μm) |
| Aluminium oxide (10 μm) | 30 | 30 | 8.58 | 16.42 | 450 |
| Aluminium oxide (50 μm) | 30 | 30 | 7.9 | 16.94 | 50 |
| Aluminium oxide (50 μm) | 30 | 15 | 7.57 | 12 | 375 |
| Aluminium oxide (50 μm) | 15 | 30 | 8.39 | 26.23 | <10 |
| Aluminium oxide (50 μm) | 45 | 30 | 11.23 | 16.1 | 100 |
| Aluminium oxide (50 μm) | 90 | 30 | 11.73 | 11.79 | 500 |
| Crushed glass (50 μm) | 30 | 30 | 6.85 | 13.37 | 375 |
| Crushed glass (50 μm) | 45 | 30 | 6.96 | 13.32 | 430 |
| Glass bead (50 μm) | 30 | 30 | 8.73 | 14.93 | 350 |
| Pumice (50 μm) | 30 | 30 | 8.31 | 14.01 | 75 |
| Silicon carbide (50 μm) | 30 | 30 | 1.31 | 17.76 | 425 |
| Sodium bicarbonate (50 μm) | 30 | 30 | 6.06 | 11.06 | 30 |
| Plastic (50 μm) | 30 | 30 | 5.54 | 9.63 | 20 |
