The YX-420ST/425S open-air DTH drill rig is a new equipment upgraded in response to the country's environmental protection requirements. Equipped with Yuchai's four-cylinder National III engine to meet the country's requirements for emissions and environmental protection. Adopt plunger walking motor, hemmed crawler frame and engineering four-wheel belt to increase working pressure and increase climbing performance.

Increase the pitch and boom cylinders to meet the requirements of extreme positions. At the same time, the hydraulic system is upgraded to increase the system flow and increase the rotation speed. The gyrator adopts a double-motor reducer to increase the turning torque and speed. To increase the lifting cylinder and chain, improve the lifting force and reliability. Reinforce the guide rail and increase the upper and lower wear plates of the sliding plate to extend the service life. The guide rail adopts inclined installation, which is convenient for operation and observation. The cover is folded with thicker profiles to increase the strength and rigidity, and the hoisting ring is added to facilitate loading, unloading and hoisting. The YX-420ST/425S type adds a dust collector and adopts double dust catching oil cylinders, which is more environmentally friendly and reliable when working.