Vega T125H040A Impactech Hex 4mm Insert Bits feature a patented spiral torsion zone that absorbs impact resulting in longer tool life. Vega T125H040A Impactech Hex 4mm Insert Bits precision engineered tips are manufactured with a proprietary CNC machining process and are made from S2 Modified impact resistant steel. Vega T125H040A Impactech Hex 4mm Insert Bits are tested to outperform all leading brands in life cycle and tip failure testing.