Rod Shaft

The rod shaft is the central cylindrical component of a hydraulic cylinder piston rod, serving as the primary load-bearing element that transfers linear force from the piston to external machinery. It maintains alignment, withstands compressive and tensile stresses, and provides the interface for mounting and connection. Typically manufactured from chrome-plated steel, the rod shaft is precision-machined to meet specified dimensional and surface finish requirements. Standard diameters range from 20 to 200 mm per ISO 6195, with custom diameters available. Lengths typically span 200 to 3000 mm, extendable up to 6000 mm on request. Surface roughness is held to Ra 0.2–0.4 μm per ISO 1302, critical for seal life and friction. Straightness is maintained within 0.05 mm per 1000 mm per ISO 1101 to ensure smooth operation and even wear. The surface is induction hardened to HRC 50–60 per ISO 6508, with a chrome layer thickness of 20–50 μm per ISO 6158 for corrosion resistance and hardness. Tensile strength ranges from 600 to 900 MPa, and yield strength from 355 to 700 MPa, both per ISO 6892, depending on material grade. Operating temperature is limited to -20 to 80 °C due to seals and material constraints. Approximate weight for standard sizes is 5 to 150 kg. These values are reference ranges; actual specifications must be confirmed with the legal manufacturer or supplier for the specific model and application. The rod shaft is a critical component in hydraulic systems, and its proper selection and maintenance are essential for reliable operation.

The rod shaft converts hydraulic pressure from the piston into mechanical linear motion. As hydraulic fluid acts on the piston, the force is transmitted through the rod shaft, which moves linearly within the cylinder barrel and gland, enabling pushing or pulling actions in industrial machinery. The rod shaft must maintain precise alignment and surface finish to minimize friction and wear on seals, ensuring efficient force transfer and long service life. Its material and hardness are selected to withstand the compressive and tensile stresses encountered during operation, while the chrome plating provides corrosion resistance and reduces friction. The rod shaft's straightness and surface roughness directly affect the performance and durability of the hydraulic cylinder, making these parameters critical for proper function.