Normally larger abrasives produce a rougher surface and provide greater edge rounding. Larger abrasives generally produce a rougher surface and provide greater edge rounding. The amount of stock removed over time on the workpiece increases roughly in proportion to the size of the abrasive (the larger the abrasive, the greater the stock removal). Small abrasives provide less stock removal and less surface roughness due to better embedding of the workpiece.
Comparison Tristar small - Tristar large
Surface comparison of
blank – Finishing with small abrasives - with large abrasives
In the example, you can see aluminium profiles that were machined with abrasives of different sizes in an identical process. The roughness here increases from Ra 0.2µ (triangle 10/10) to twice the value of Ra 0.4µ (triangle 25/25) due to the use of larger abrasives. The edge rounding also increases disproportionately from 0.245mm (triangle 10/10) to 0.932mm (triangle 25/25).
This can also be observed well when working with new abrasives that have not yet experienced any wear. Here you get the highest surface roughness for given process parameters. Due to the abrasion of the abrasives, a "working mixture" of large and small abrasives is created when new abrasives are regularly refilled, which leads to a lower surface roughness due to the better embedding of the workpieces. However, the stock removal and edge rounding decreases as the small fractions of abrasives increase.