Hardened Bearing Shaft

A hardened bearing shaft (or precision linear shaft) serves as the foundational smooth raceway for linear ball bearings, bushings, and rollers. Because the rolling elements of a bearing ride directly on the surface, the shaft must feature a highly controlled surface hardness, dimensional tolerance, and mirror finish to prevent rapid mechanical wear and binding.

• Hardness (typically 58 to 64 HRC): Most precision shafts undergo induction case hardening. This creates a high-wear outer layer while maintaining a ductile core to absorb shock loads without snapping. Standard steel grades like Cf53 or 440C Stainless Steel are commonly used. 
• Tolerance Class (commonly h6): Centerless grinding ensures that outer diameter deviations remain microscopic, vital for minimizing slop, maximizing radial load handling, and matching bearing inner rings precisely. 
• Surface Roughness: Micro-ground finishes reduce drag and friction, protecting recirculating ball systems from premature degradation.
• Material consists of #45 Carbon Steel. Accuracy up to level G6 and class H7
• Straightness 0.07/1000mm
• Hardness Thickness 0.8-3mm
• Face Roughness ra0.10m-ra0.35m
• Hardened thickness 0.015-0.02mm