1. Hardness: a solid line of defense against wear
Hardness is a measure of the material's ability to resist local pressure deformation or scratches. For the spindle, high hardness means stronger wear resistance and longer service life. Under high-speed rotation and high-load operating conditions, the spindle surface frequently contacts the tool and workpiece, which is prone to friction and wear. Therefore, choosing a material with high hardness can effectively reduce this wear, maintain the spindle's dimensional accuracy and shape stability, and thus ensure processing quality and efficiency.

Stainless steel is widely used for its good corrosion resistance, certain hardness and toughness, especially in situations where corrosion resistance and certain strength need to be considered at the same time. Carbon steel can greatly improve its hardness through heat treatment, becoming one of the commonly used materials for manufacturing high-precision spindles, but its corrosion resistance is relatively weak and requires additional protection measures. Alloy steel optimizes the mechanical properties and corrosion resistance of the material by adding alloying elements (such as chromium, nickel, molybdenum, etc.), and is an ideal choice for manufacturing high-performance spindles, especially under extreme working conditions.

2. Strength: Ensure a stable load-bearing foundation
Strength refers to the ability of a material to resist external forces without breaking or plastic deformation. For the spindle, sufficient strength is the key to ensure that it does not undergo plastic deformation or breakage when rotating at high speed and bearing heavy loads. The strength of the spindle is not only related to the stability of the machining process, but also directly affects the machining accuracy and the surface quality of the workpiece.

When selecting the spindle material, in addition to considering hardness, its tensile strength, yield strength and fatigue strength must also be considered comprehensively. For example, some high-strength alloy steels can not only provide excellent hardness, but also show excellent fatigue resistance while maintaining high toughness, which is particularly important for precision machining equipment that operates continuously for a long time. In addition, heat treatment technology (such as quenching and tempering) can further adjust the microstructure of the material, improve its comprehensive mechanical properties, and meet specific application requirements.

3. Comprehensive consideration of material selection
In practical applications, the material selection of precision hardware spindles is not determined by a single factor, but requires comprehensive consideration of multiple factors such as working environment, processing requirements, and cost budget. For example, for occasions that require frequent contact with corrosive media, even if some alloy steels have higher strength and hardness, if they do not have sufficient corrosion resistance, they may not be the best choice. At this time, it may be necessary to consider stainless steel or materials with special surface treatment.

At the same time, with the development of materials science, new materials such as ceramics and composite materials have gradually been used in spindle manufacturing. These materials have shown unique advantages in hardness, strength, wear resistance, thermal stability, etc., providing more possibilities for precision machining. However, the application of these new materials is also accompanied by challenges such as high processing difficulty and high cost. It is necessary to weigh the pros and cons and make reasonable choices.