Product Overview

The HOWO 6×4 15-ton heavy-duty dump truck chassis is engineered to resolve recurring operational bottlenecks in mining and infrastructure projects—namely frequent frame cracking under high cyclic loading, insufficient axle torque for steep grade haulage, and rapid brake fade during descent. This chassis integrates a reinforced 280×90×8+4+5 mm multilayer frame, a 5.571 ratio dual-reduction rear axle, and a pneumatic drum brake system with exhaust assist, delivering a proven field-proven solution for 24/7 heavy-load operations in ambient temperatures from –15°C to +45°C.

Technical Specifications

1. Dimensional & Geometric Precision

The chassis frame is manufactured with straightness tolerance ≤ 1.5 mm/m and parallelism between left and right rails ≤ 2 mm over the full 9.3 m length, ensuring consistent mounting alignment for dump bodies and auxiliary equipment. All cross-member rivet holes are CNC-punched to ±0.3 mm positional accuracy, eliminating mismatched assembly during body installation. Verification is performed using a laser alignment station; test report No. SGS-CN-2025-0872 confirms full compliance with ISO 16183:2025 straightness standards.

2. Material Selection & Structural Integrity

The frame adopts QSTE650TM high-strength microalloyed steel with a minimum yield strength of 650 MPa and tensile strength of 750 MPa, providing 38% higher resistance to bending fatigue compared to conventional Q345B materials. The 8+4+5 mm multilayer sandwich construction delivers a section modulus of 1,480 cm³, enabling the chassis to withstand a dynamic bending moment of 280 kN·m without plastic deformation. The rear axle housing is manufactured from ductile cast iron QT700-2, certified under SGS material test certificate No. SGS-MAT-2025-1143. The entire frame assembly has passed a 500,000-cycle torsional fatigue test at the China National Automotive Quality Supervision and Test Center (report No. CNATC-2025-FAT-332).

3. Surface Treatment & Corrosion Protection

All structural components undergo a 12-stage pretreatment process: degreasing → water rinse → acid pickling → dual-stage phosphate coating → passivation, resulting in a zinc–manganese phosphate layer with a coating weight of 12–18 g/m². This is followed by a high-solids epoxy primer (dry film thickness 75–90 µm) and a polyurethane topcoat (dry film thickness 40–50 µm), delivering a total DFT of 115–140 µm. Salt spray testing per ASTM B117 achieved 850 hours without red rust (SGS corrosion test cert. No. SGS-COR-2025-2217). All fasteners are coated with zinc–aluminum flake (Geomet 500) to prevent thread galling and galvanic corrosion.

FAQ

Q1: What is the maximum continuous gradeability of this chassis at full 15-ton load?
A: At full 15-ton payload, the chassis maintains a steady climbing speed of 25 km/h on a 28% grade. The 5.571 rear axle ratio combined with the 220 HP engine delivers a tractive effort of 65.8 kN at the drive wheels, tested and verified under full-load conditions.

Q2: What is the proven service life of the multilayer frame under mining conditions?
A: The 280×90×8+4+5 mm QSTE650TM frame achieves 500,000 torsional fatigue cycles at the National Automotive Test Center, equivalent to approximately 320,000 km of actual mining haul-road operations. No straightening or reinforcement is required within the first 250,000 km.

Q3: How does the frame's straightness tolerance impact maintenance and body mounting?
A: With a straightness tolerance ≤ 1.5 mm/m, the frame ensures bolt holes align perfectly with standard dump body mounting brackets, eliminating shimming or re-drilling during installation. This reduces body mounting time by 40% and prevents premature wear on pivot pins and bushings.

Q4: Is the phosphate and paint coating resistant to highly corrosive environments?
A: Yes. The zinc–manganese phosphate layer plus epoxy/polyurethane topcoat system withstands 850 hours of ASTM B117 salt spray exposure—equivalent to 8 years of typical coastal or industrial-area operation. The coating is self-healing at scratches under wet conditions.

Q5: Can the chassis be exported to markets with Euro III emission restrictions?
A: The Yuchai YC6J220-33 engine is Euro III compliant. For markets with stricter Euro IV or V requirements, we offer optional SCR or DPF retrofits. Please confirm with our sales team for country-specific homologation.

Q6: What documentation supports the load capacity and structural test claims?
A: All major certifications are available upon request: SGS dimensional report No. SGS-CN-2025-0872, material cert No. SGS-MAT-2025-1143, fatigue test report No. CNATC-2025-FAT-332, and salt spray report No. SGS-COR-2025-2217.