Effect of cutting speed in single point diamond turning of (100)Ge

•On-axis single point diamond turning of (100)Ge resulted in three distinct radial lobes with similar surface topographies.•The topography changed with an increase in cutting speed, leading to a reduction or elimination of surface fracture.•Cutting and thrust forces decreased with the increase in cutting speed.•The obtained results point to a possible shift in material response as cutting speed is increased.