Abrasion occurs in pumps that handle abrasive fluids. Particles in the fluids cause scratches and microscopic scoring in the outer layers of the pump material. Abrasion, in other words, is a type of wear. The amount of abrasive wear that a surface experiences depends on various factors, including the size, sharpness, hardness, density and concentration of the abrasive particles. The abrasion resistance of various materials can be measured using the mechanical Taber Abraser test. Abrasive wear removes material. This does more than just shorten the service life of the pump; it also shortens the service life of other components that come into contact with the pumped fluid. However, steps can be taken to reduce abrasion and extend component service life. One common tactic is to reduce particle concentration and flow rates for centrifugal pumps. In addition, hard or abrasion-resistant pump materials or pump speed controllers can slow down the loss of material to abrasive wear.