In practice, abrasive materials will vary considerably in hardness, crushing strength and shape from the sand specified in the ASTM standards. Rankings of wear resistance obtained with quartz sand may bear little relation to wear with other abradants such as subangular quartz, silica sand, alumina, sinter, coke and coal. The absolute wear rate and relative ranking of materials are greatly influenced by the following parameters:
1. Particle loading, the nominal load carried by each particle of abradant
2. Particle size
3. Particle speed or cutting speed
4. Moisture level
5. Abradant properties, namely hardness and crushing strength
6. Abradant particle shape or angularity