Ground precision shafts

Frequently asked questions — Shafts

• How do you choose between Cr40 steel and stainless steel for a guide shaft?

  Induction-hardened Cr40 steel is the standard material, offering a surface hardness of HRC 60-62 for high wear resistance, while retaining a ductile core. For damp or aggressive environments, hardened AISI 440C or non-hardened AISI 303 stainless steel shafts are recommended. The choice therefore depends directly on the operating conditions of your linear guide system.
• What is the use of hollow shafts compared with solid models?

  Hollow shaft variants are specifically designed to allow cables or hoses to pass through the shaft. This configuration offers a notable saving in space, particularly suited to integration in Cartesian robots. Apart from this need for internal routing, the technical characteristics of precision and hardness remain comparable to standard solid shafts.
• When should intermediate shaft supports be installed?

  Intermediate shaft supports, designated SH or MSH, are essential when the stroke length exceeds 50 to 80 times the shaft diameter. Their installation limits deflection under load, thereby ensuring that the precision and rigidity required for the correct operation of ball bushing systems are maintained over long distances.
• What dimensional and geometric precision can I expect from these shafts?

  Dimensional accuracy of the shafts follows the h6 tolerance, illustrated for example by a 20 mm diameter with a tolerance of -0/-0.013 mm. The ground surface finish guarantees an Ra value between 0.2 and 0.4 µm. Finally, the straightness of the shaft is rigorously controlled with a guarantee of 0.2 mm per metre maximum to ensure the quality of the rolling action.
• Is it possible to obtain custom-machined shafts?

  Yes, to meet specific mounting requirements, shafts can be supplied with ends machined to order. Machining options include internal tapping, the creation of flats or the addition of flanges. This customisation is available for shaft lengths of up to 6 metres, thereby facilitating direct integration into your mechanical assemblies.