420 Stainless Steel Linear Shafts

420 stainless steel linear shafting consists of hardened, corrosion-resistant round shafts for plain linear bearings and linear ball bearings. The number 420 identifies a martensitic stainless steel grade with less carbon than 440C stainless steel, providing greater toughness and easier machining while still allowing the running surface to be hardened to approximately RC 50+. RC means Rockwell C, a hardness scale used for hardened steels; a rating of RC 50+ indicates a hard, wear-resistant bearing surface. Compared with 420, 440C can achieve greater hardness and wear resistance but is generally more difficult to machine. The 300 series, including 304 and 316 stainless steel, usually provides greater corrosion resistance but cannot be heat hardened to the same degree, making it better suited to plain linear bearings than to rolling-element linear ball bearings.

PBC Linear 420 stainless steel shafting is compatible with Simplicity® FrelonGOLD® lined plain linear bearings and linear ball bearings. Its 8–12 RMS surface finish supports smooth bearing travel, faster plain-bearing break-in, and effective self-lubricating Frelon® liner transfer. RMS means root mean square, a measurement of microscopic surface roughness commonly expressed in microinches; a lower RMS value indicates a smoother surface.

Inch and metric sizes are available as solid round or pre-drilled shafting, cut to length or supplied in full lengths. On pre-drilled shafting, hole spacing is the center-to-center distance between adjacent mounting holes. An important metric is the distance between the first hole and at least one end of the shaft. Hole-spacing tolerance is the permitted variation from the specified hole locations, while length tolerance is the permitted variation between the ordered shaft length and the finished shaft length. These tolerances depend on the selected shaft diameter and configuration. Custom end machining can include chamfers, which are angled cuts that remove a sharp shaft edge; threaded diameters, which are reduced shaft ends with external screw threads; and tapping, which creates internal threads inside a drilled hole for accepting a screw or bolt.

• 420 martensitic stainless steel with corrosion resistance and high toughness
• Lower carbon than 440C for improved machinability and toughness
• Approximately RC 50+ hardness for a wear-resistant bearing surface
• RC means Rockwell C, the hardness scale used for hardened steel
• Compatible with Simplicity® FrelonGOLD® plain linear bearings and linear ball bearings
• Available in inch and metric diameters
• Choose solid round or pre-drilled shafting
• Hole spacing is measured center to center between adjacent mounting holes
• Hole-spacing tolerance defines allowable variation in mounting-hole locations
• Length tolerance defines allowable variation from the ordered shaft length
• Available cut to length or in full lengths
• Custom end machining includes chamfers, threaded diameters, and tapping
• Chamfers remove sharp edges with an angled cut
• Threaded diameters are reduced shaft ends with external threads
• Tapping creates internal threads inside a drilled hole
• Surface finish: 8–12 RMS root-mean-square roughness
• Diameter tolerance: Class L