In HC20 Hydraulic Rock Drill (or Hydraulic Drifter) systems, the Carter 86668704 (internal housing) is the “structural backbone”—it serves as the main carrier for core components like the hydraulic motor, impact piston, and control valve, while withstanding external vibration (up to 1400 bpm during drilling) and internal hydraulic pressure (up to 1800 psi). As a long-service-life part, its integrity directly determines the drill’s operational safety: a cracked or deformed housing can cause internal components to shift, leading to severe failures (e.g., motor seizing or piston jamming) that cost $3,000+ in repairs and 2-3 days of unplanned downtime.

1. High durability: Made of heat-treated cast steel (tensile strength ≥ 700 MPa), it resists cracks and deformation even under long-term heavy use—supporting the “long-term use, replace only when damaged” requirement.
2. Precision fit: Mounting holes and component grooves are machined to ±0.003mm tolerance, ensuring seamless assembly with HC20’s internal parts—no on-site modifications needed.
3. Component protection: The inner cavity features reinforced ribs that absorb vibration, reducing stress on the motor and piston and extending their service life.