Soft Percussion and its Benefits for Dry Core Drilling

January 18, 2024

Soft Percussion and its Benefits for DryCore Drilling

Soft percussion is a very useful feature for a dry diamond core drill. Here we will discuss what it is, what it is not, and what its advantages are for dry coring in masonry materials and concrete. It is a mechanical feature of the drill’s gearbox which, when engaged, forces the spindle to jump forward and back a small amount as the spindle rotates.  

AGP DM62 Dry Drilling Motor

This feature is known under a number of different names, such as “soft impact”, “micro percussion”, etc.  These all have the same meaning, and they are contrasted with the much more aggressive percussion action found in rotary hammer drills. Their hard impact function works with a carbide-tipped masonry twist drill to hammer the bit into the workpiece, thus speeding the drilling process.

Soft percussion works in a different way. The percussion pulses are much smaller in amplitude and are not intended to hammer the bit into the work material. Rather, soft percussion does two things: Firstly, it agitates the dust in the kerf, keeping it from getting trapped and allowing it to be sucked in by a vacuum cleaner. Secondly, it keeps the diamond segments sharp.

AGP DME52D Dry Drilling Motor

The way that diamond segments work is that they have a bond matrix which holds the diamond grains throughout. As the bond wears, new diamond grains are continually exposed, keeping the segments sharp. If the bond doesn’t wear fast enough, the segments will polish smooth. Diamond segments going dull is exacerbated by dry drilling, and the soft percussion agitates the bond to keep the diamonds protruding sharply. Without soft percussion, the operator would have to take time to sharpen the bit on a sharpening stone much more often.

The soft percussion function is switchable, so if the operator deems that the diamonds are staying sharp without it, the percussion can be switched off. If the core bit gets dull, the operator can switch the percussion back on. Considering the benefits of soft percussion, it is certainly an essential feature for the ever-growing application of dry core drilling.