Where are stainless steel linear modules used, and what advantages do they have?

Not all stainless steels are the same

Two types of stainless steel are used in linear drive technology: X46/high grade steel and 304/316 stainless steel. X46/high grade steel is hardened stainless steel while 304/316 stainless steel is non-hardened stainless steel.

Steel linear module in a lab production line with bottles.

Hardened V2A stainless steel

Linear modules and linear axis guides of hardened stainless steel are usually offered in combination with recirculating ball bearing systems and roller bearing guides. The guide system's metal balls require a strong running surface to prevent them from creating grooves. Hardened stainless steel such as AISI 420C, AISI 440B, and AISI 440C has a relatively high carbon content (more than 0.5%), which is necessary for hardening in the first place. This means that hardened stainless steel is only somewhat corrosion-resistant. The necessary lubrication for recirculating ball bearing systems and roller bearing guides entails a danger of contaminating products, which is undesirable in many areas.

Drylin plain bearing with arrows showing sliding motion instead of rolling.

Non-hardened V4A stainless steel

Non-hardened stainless steel has a lower carbon content and inferior hardness, but is much more resistant to corrosion and aggressive cleaning agents and chemicals. Because recirculating ball bearing systems and roller bearing guides are not as well suited to moving on non-hardened stainless steel, a plain bearing system is used. The force exerted at particular points on the rail material is changed to area force. The load on the linear rail is distributed across a greater area, avoiding material wear.

The principle: "sliding instead of rolling"

The advantages of plain bearing liners over a recirculating ball bearing system

The plain bearing liners made of high-performance polymers used by igus are lubrication-free, maintenance-free and therefore the ideal partner for stainless-steel linear modules. The combination of plain bearing system and stainless-steel linear axis can be found in certain applications due to the advantages of the linear drive system.

Stainless steel linear modules in application

Wherever it is important to dispense with lubrication and machine components come into contact with food, strong cleaning agents or even chemicals, stainless steel is necessary. To minimise maintenance and cleaning effort, igus has developed linear modules and linear axes for precisely this requirement - drylin linear modules made of stainless steel.