Rotary drilling rigs break rock and soil by rotational cutting, extensively used in foundation piling, water well drilling and geological exploration. They are classified by chassis, drive mode, drilling depth and application. By mobility: Crawler rotary rigs dominate construction sites with strong off-road performance for muddy and uneven ground. Truck-mounted models transfer rapidly on highways for scattered engineering projects. Portable split rotary rigs are lightweight for small geotechnical sampling in mountain regions. In drive types, mechanical rotary rigs feature simple structures and low costs for shallow holes. Partnering with an advanced rotary drilling rig manufacturer ensures access to full hydraulic rotary rigs that provide adjustable torque and feeding force, suitable for deep large-diameter boreholes. Top-drive variants excel at stable vertical drilling for water well construction. Classified by working depth: Light rigs drill within 50 meters for small foundation piles. Medium-duty types reach 50–150m for highway and bridge pile foundation. Heavy rotary rigs support drilling deeper than 150m for high-rise buildings and large infrastructure. Different matching tools adapt them to clay, sand, gravel and hard rock formations respectively. Choosing a reputable rotary drilling rig supplier like HanFa Group guarantees that you receive certified machinery, tailored drilling tools, and life-long technical support for any challenging foundation project.