Ø20 mm Hard Chrome Plated Ground Shaft (No Hardening)

Detailed Product Review

Designed to Mermak CNC engineering standards, the Ø20 mm Hard Chrome Plated Ground Shaft is a component developed to form the basis of precise and reliable linear motion in industrial automation systems. The primary function of this shaft is to provide a low-friction, high-accuracy, and environmentally resistant guide surface for linear bearings, slide bearings, or similar moving elements. Its working principle is based on the shaft’s ultra-precisely ground surface providing minimal contact area and an optimized friction coefficient with moving components, thereby reducing kinetic energy losses and increasing motion fluidity. The hard chrome plating applied over a high-quality carbon steel core protects the shaft’s surface against corrosion, oxidation, and wear, while also increasing surface hardness to extend the system’s operational life. This design is optimized to deliver optimal performance, especially in applications where surface quality, corrosion resistance, and precise dimensional tolerances are critical, rather than the core hardness of the shaft.

The material structure of this shaft consists of a special carbon steel alloy (e.g., Ck45 or equivalent) offering high strength, machinability, and cost-effectiveness. The absence of core hardening allows the shaft’s internal structure to remain more ductile, facilitating secondary machining operations (cutting, drilling, threading, etc.) and minimizing the risk of thermal deformation. The hard chrome plating on the surface, with a thickness in the micron range, increases the shaft’s surface hardness (minimum 60 HRC), providing resistance against wear and scratches. In terms of system integration, this shaft exhibits excellent compatibility with components such as linear bearings that do not require hardening, slide bearings, and aluminum housings of the SK/SHF series. This compatibility eliminates the risk of damaging the internal structure of the bearings and offers ease of assembly. Application areas cover a wide range, from automatic assembly lines requiring precise positioning, to low and medium load conveyor systems, guide systems in textile and packaging machines, and linear actuators in measurement and control devices. The shaft’s straightness tolerance and g6 diameter accuracy form the basis for repeatable and reliable motion capability in these systems.

Superior Surface Morphology and Tribological Performance: The Ra ≤ 0.4 µm surface roughness value achieved through the precise grinding process of this shaft is a critical parameter in tribological systems. This micron-level smoothness significantly minimizes the friction coefficient (μ) between the linear bearings or slide bearings and the shaft surface. Low friction increases the system’s overall energy efficiency by reducing kinetic energy losses and lowers operational costs. Furthermore, the smooth surface enhances its capacity to absorb vibrations and noise generated during motion, providing a more stable and quieter operating environment. This morphology allows the lubricant film to distribute more homogeneously on the shaft surface, supporting the formation of hydrostatic or hydrodynamic lubrication conditions, which reduces wear rates and extends bearing life. Minimizing micro-pits and peaks on the surface reduces localized stress concentrations on bearing elements and positively affects fatigue life.

Enhanced Corrosion and Wear Resistance: The hard chrome plating applied to the shaft’s surface forms a superior barrier against environmental corrosion factors through electrochemical passivation. Chrome, with its high chemical inertness, prevents direct contact with aggressive substances such as moisture, industrial vapors, mild acidic or basic solutions, and dust. This coating provides critical protection, especially in systems where different metal pairs are used together, posing a risk of galvanic corrosion. The minimum 60 HRC hardness of the chrome layer makes the shaft’s surface resistant to abrasive wear, scratches, and surface fatigue caused by abrasive particles. This feature extends the shaft’s operational life, dilutes maintenance intervals, and reduces spare part replacement costs, thereby optimizing the total cost of ownership (TCO). High wear resistance helps maintain the shaft’s dimensional stability, guaranteeing long-term precise motion capability.

Optimized Mechanical Machinability and System Integration: The absence of core hardening in this shaft offers a significant advantage in engineering applications. The lack of hardening facilitates secondary machining operations such as cutting, drilling, threading, and milling. This allows the shaft to be easily modified in projects with special mounting requirements, such as drilling holes for sensor mounting or creating threads for special fasteners. While hardened shafts often increase the risk of cracking or tool wear during such operations, the unhardened core minimizes these risks. Furthermore, this feature ensures seamless integration of the shaft with aluminum housings of the SK and SHF series, and with linear bearings that do not require hardening (e.g., slide bearings or low-load ball bearings). These bearing systems do not depend on the shaft’s core hardness but operate by focusing on surface quality and dimensional tolerance. This compatibility offers designers greater flexibility in material selection and system configuration, thus facilitating adaptation to various industrial designs. Mermak has 16 years of experience supplying high-quality industrial components to markets including the United Kingdom, United States, Canada, Australia, Ireland, New Zealand, and South Africa, alongside similar countries and international markets. Our Ankara Uzay Sanayi factory/warehouse ensures up-to-date stock quantities and prices on our website. Stocked products are dispatched directly from our warehouse, eliminating production waiting times. We ensure careful packaging, meticulous invoice/document follow-up, and utilize reliable logistics partners. The Mermak team closely monitors the shipment process, and product videos or factory viewings are available upon request via WhatsApp or our contact channels.

Technical Specifications and Capacity