The soil drilling rig is a machine used for drilling boreholes in the ground for soil  investigation and sampling. It consists of a drill mast, power head, drill rods and drill bits. The drill mast provides a stable frame to support the drill rods. The power head uses hydraulic force to rotate the drill rods and drill bits to penetrate the ground. Drill rods are added as the borehole gets deeper. Drill bits at the end of the drill rods cut the soil and rock to advance the borehole. The drilling rig enables fast and efficient soil drilling at various depths.