High-Strength Dome Nut for Hydraulic Rock Drills This dome nut is engineered to secure components in hydraulic rock drill assemblies, providing reliable clamping force in high-vibration mining environments. Constructed from 8.8 grade high-tensile steel, it combines tensile strength (800MPa) with ductility, ensuring resistance to loosening under repetitive impact loads.
Key Performance Attributes
Material & Durability:
8.8 grade high-tensile steel (ISO 898-2) achieves 800MPa tensile strength and 640MPa yield strength, delivering a 20kN clamping load—suitable for securing critical components like bearing housings and flange connections .
8μm zinc plating (ASTM B633) offers 72-hour salt spray resistance (ASTM B117), protecting against corrosion in damp underground mines and reducing maintenance needs .
Design & Precision:
The dome-shaped head prevents snagging on debris, while the serrated underhead creates a mechanical lock, reducing vibration-induced loosening by 40% compared to smooth underhead nuts .
M20 x 2.5mm threads (ISO 898-2) with 6g thread fit ensure compatible mating with standard shafts, while IT8 tolerance guarantees consistent performance across production batches .
Operational Reliability:
Rated for 10,000 cycles under recommended torque (350Nm), it maintains clamping force in extreme temperatures (-40°C to +120°C). The 30mm hexagonal drive facilitates easy installation with standard tools, simplifying on-site maintenance .
Applications
Hydraulic Rock Drills: Secures bearing retainers, cylinder end caps, and shaft collars in standard drill models.
Mining Equipment: Compatible with tunneling machines, quarry drills, and exploration rigs requiring high-strength fasteners.
