B reamer: function: keep the aperture and keep drilling stability. The grade reamer is designed with spiral sinks and polycrystalline sintering process.
C grade reamer: function: maintain aperture, repair hole wall, improve drilling stability. The grade reamer is designed with spiral flume, and diamond + polycrystalline composite sintering process.
D grade reamer: function: maintain aperture, repair hole wall, improve drilling stability. The grade reamer adopts spiral flume design, wide working face design, diamond + reinforced polycrystalline composite sintering process.