Dongfeng KR truck parts first step Left connecting bracket 8406161-C5900

Built to withstand repeated foot pressure (up to 150kg per step) and harsh working conditions, the bracket uses 5mm-thick Q345B low-alloy steel with a yield strength of 345MPa. The material undergoes hot-rolled forming and robotic welding to create a rigid, L-shaped structure with reinforced corners (8mm thickness at stress points) that distribute load evenly across the cab sill. Finite Element Analysis (FEA) testing confirms it endures 100,000+ step cycles (equivalent to 8 years of daily use) without deformation, even under uneven foot pressure. The bracket’s pedal-mounting surface features a 3mm-deep ribbed design that enhances grip with the step’s underside, preventing slippage during installation. Unlike thin steel or aluminum brackets that bend under load, this heavy-duty design ensures the first step remains stable and safe for drivers and passengers

Engineered to resist corrosion from road salt, mud, and water splashes (critical for under-step components), the bracket undergoes a multi-stage protective treatment. It starts with a zinc phosphate primer (60μm thickness) to improve coating adhesion, followed by an electrophoretic paint layer (80μm) that seals against moisture. A final UV-stabilized polyester topcoat (50μm, matching the KR’s chassis color) resists chipping, fading, and chemical damage from diesel or cleaning agents. This coating system passes 1,000 hours of neutral salt spray testing (equivalent to 7 years of road salt exposure) without rust. The mounting holes are also treated with anti-seize compound to prevent thread corrosion, ensuring easy removal during maintenance. Unlike uncoated brackets that rust within 1–2 years, this design maintains structural integrity in all weather conditions

Designed to minimize rattling and noise during driving, the bracket integrates rubber damping elements at key contact points. A 3mm-thick EPDM rubber pad (pre-installed on the cab sill contact surface) absorbs 60% of vibration transfer between the bracket and cab, eliminating metal-to-metal noise. The pedal mounting holes include rubber washers (included) that cushion the step against road vibrations, preventing loosening over time. The bracket’s edges are deburred and rounded to avoid abrasion of adjacent components (e.g., door weatherstripping), further reducing noise and wear. Unlike rigid metal brackets that amplify vibration, this design ensures a quiet cabin environment and extends the lifespan of connected components

Designed for hassle-free replacement by fleet technicians or DIY owners, the bracket simplifies installation with precision features and complete hardware. It includes 4 M10×30mm high-tensile bolts, lock washers, rubber damping pads, and a torque guide (specifying 55N·m for secure mounting). Two laser-etched alignment lines on the bracket align with marks on the KR’s left cab sill, reducing installation time to 15–20 minutes. Installation steps: clean the cab sill and step mounting surfaces, attach the rubber pad to the bracket, align the marks, secure the bolts to the specified torque, then mount the first step pedal to the bracket. No post-installation adjustment is needed—the bracket’s pre-machined holes ensure the step sits perfectly level. Each unit undergoes dimensional checks via CMM, load testing, and coating adhesion verification, backed by a 24-month warranty against defects (e.g., bending, rusting, or weld failure)