Materials for Linear Guideways

Figure 1: Roller profile rail guideways.

Linear guideways are widely used in transmission system and have many characteristics such as high hardness, high accuracy, etc. These are largely attributed to the advanced material they use. The commonly used materials for linear guideways are high-carbon chromium bearing steel, carburizing steels for bearing, commercial aluminum, stainless steel, and carbon steel. The following will briefly introduce these five types.

1. High-carbon Chromium Bearing Steel

Bearing steel is called the king of steel by people in the steelmaking industry. High-carbon chromium bearing steel is a large type of bearing steel, and is the most commonly used steel for the manufacture of bearings and bearing parts. The most frequently deployed types are GCr15 and GCr15SiMn.

The vast majority of bearing rings and rolling elements, including linear guideways, are made of special steel. The rings and rolling elements are made of high-carbon chromium bearing steel (GCr15 and GCr15SiMn and ZGCr15 and ZGCr15SiMn), and the parts have high hardness.
The rings and rollers made of GCr15 and ZGCr15 materials are HRc61~65, and the steel balls are HRc62~66; the rings and rollers made of GCr15SiMn and ZGCr15SiMn materials are HRc60~64, and the steel balls are HRc60~66.

Bearings made of high-carbon steel chromium bearing steel are generally applicable to a working temperature of -40 to 130 degrees Celsius, which can meet the requirements of general machinery. After high-carbon chromium bearing steel bearing parts are tempered at high temperature, the working temperature can be as high as 250 degrees Celsius.

2. Carburizing Bearing Steels

Figure 2: Carburizing bearing steels.

Compared with high carbon chromium bearing steel, carburizing bearing steel has relatively lower hardness (HRC 45.2), lower wear resistance, but is less brittle.
Carburizing bearing steel is the support of various mechanical components. Its working environment may be ultra-high temperature, ultra-low temperature, strong (slightly) vacuum, or strong impact, high wear and ultra-high speed. The structural characteristics and working conditions of carburized bearing steel enable bearing parts to have high hardness, wear resistance, contact fatigue strength, good toughness, dimensional stability, corrosion resistance and hot and cold processing properties.

3. Industrial Aluminum

In some places where the load capacity is not high, industrial aluminum is usually used. As we all know, industrial aluminum is an alloy material with aluminum as the main component. The material of aluminum alloy is lighter, the hardness can meet the requirements of the guideway, and it can also reduce the weight of the equipment to a certain extent. The surface of aluminum is bright and silver-white, and has good corrosion resistance, which is suitable for the use of medical equipment and high-end equipment. Some linear modules also use high-strength aluminum alloy materials as bases, aluminum alloy sliding seat, etc.

4. Stainless Steel

Some linear guideway brands in Japan, such as Hiwin guideways, use stainless steel, which is usually represented by the letter M.

5. Carbon Steel

Carbon steel is also a linear guideway material used by many well-known brands. Generally, the higher the carbon content in carbon steel, the greater the hardness and the higher the strength, but the lower the plasticity.

Figure 3: Carbon steels.

In summary, linear guideways are generally metal, usually aluminum, because it can meet the requirements of linear guideways for various aspects such as precision and load capacity.