Sliding, Pivot and Wear Components for Machine Tools

Rolling elements are the default for a reason — they carry more load and produce less friction at speed. But a rolling bearing depends on the geometry between its elements and raceway staying clean, and a machine tool is one of the hardest places to guarantee that. Abrasive particles that reach a ball or roller score the raceway and the clearance grows until the bearing is scrap. A sliding bearing has no raceway to protect and no rolling elements to displace, so contamination that would destroy a rolling assembly is something it tolerates. For pivots, guides, and sliding surfaces that operate in chips and coolant rather than in a sealed enclosure, that tolerance often matters more than peak load rating.

Start with the four variables that narrow the field fastest: load, surface speed, operating temperature, and what the part is exposed to. Load and speed together determine whether the material can shed the frictional heat it generates, which is the usual limiting factor rather than strength alone. Temperature sets the upper bound. Exposure — coolant, cleaning chemicals, washdown, food contact — rules out materials that would otherwise fit. From there, the shortlist is usually two or three, and the choice comes down to whether you are optimizing for wear life, low friction, or cost. Published test data covers each material across these variables, so the comparison can be made on measured values rather than on datasheet descriptions.

The mating surface matters as much as the bearing. Polymer plain bearings transfer solid lubricant onto the shaft or rail during the first hours of operation, and that transfer film is what produces the low, stable coefficient of friction over service life. A surface that is too rough abrades the bearing before the film establishes; one that is too smooth gives the film nothing to key into. Hard anodized aluminum, stainless steel, and hardened shafting each pair differently with different iglide® materials — which is worth checking before specifying, because the wrong pairing can cost most of the expected service life.

It is calculable rather than estimated. Wear rate for a given material under a given load, speed, temperature, and counter-surface is measured in the igus® test laboratory, and that data underlies a service life prediction for your specific configuration. Entering the application parameters returns an expected life before you order, which is what makes a maintenance interval plannable rather than reactive. The practical value of this is less about the number itself and more about the comparison — if two materials both work and one lasts three times as long, the decision makes itself. If the prediction comes back short, that is usually a signal that load or speed is outside what the material is suited to.

It depends on how much of the existing assembly you want to keep. A bushing suits a bore that is already the right size or can be brought to it. A liner suits a flat or gently curved surface where you want to add a wear layer without changing the geometry underneath. A coating suits a complex shape that neither a bushing nor a liner will conform to, and it adds the least thickness of the three. A machined part is the answer when the geometry is specific enough that none of the standard options fit.

Most iglide® plain bearings are designed for press-fit installation into a housing bore, which is how they are retained without adhesive or fasteners. Press-fitting compresses the bearing wall slightly, so the inner diameter after installation is smaller than the free-state dimension. That is expected and accounted for in the published dimensions, but it means the housing bore tolerance directly affects the running clearance you end up with. Check the installed inner diameter rather than the free-state figure when specifying a shaft fit. For applications where press-fitting is impractical, clip bearings and flange designs with fastener mounting are available instead.

Most iglide® materials are resistant to the water-based coolants and cutting fluids used in machine tools, and several handle oils, solvents, and cleaning chemicals as well. Resistance varies by material and by concentration and temperature, though, so a material that is fine in dilute emulsion at ambient temperature may behave differently in a hot, aggressive cutting fluid. Published chemical resistance tables cover each material against common industrial media.

Yes. Several iglide® materials achieve their low-friction performance using solid lubricants other than PTFE, which matters increasingly for customers working under PFAS restrictions or anticipating them. Most iglide materials have also been tested for critical PFAS substances and do not contain any of these substances >0.1% by mass.