Round Rod in PK 3000 mm natural

Round rod in PK is polyketone in rod form, developed for turning and milling of bearings, wheels, sleeves and other rotationally symmetric parts. The material positions itself as a tough and chemically resistant alternative to POM and PA, with a few clear features that justify the choice.

Polyketone has a density around 1.25 g/cm³ and takes continuous work up to about 100 degrees. Downward the material handles -30 degrees without losing impact resistance. The fire rating is HB. Water absorption sits around 0.4 percent, which is clearly lower than PA and somewhat lower than POM, something that shows in tolerance control on parts that are to be fitted in damp or wet environments.

The biggest reason to pick PK is often the combination of toughness plus chemical resistance. The material is very impact resistant, even at low temperatures, while it also has good stiffness and high fatigue strength. That makes PK work in components under cyclic load, such as bearings, gears and links, where PA would creep and POM might crack under shock load. Friction is low and wear resistance is high, which makes the material competitive against acetal in many sliding applications.

Chemically PK takes aggressive environments unusually well. The material resists fuels, oils, many solvents and dilute acids better than POM. That opens the door to pump parts, valve stems, dosing systems and stuffing boxes in the chemical industry where standard plastics would quickly deform or crack.

The round rod is typically used for plain bearings, guide bushings, thrust bearings, stuffing box sleeves and small gears. In food machinery the material shows up in conveyor parts that meet cleaning agents and process fluids. In vehicles PK is used in driveline components and fuel systems. For the designer, PK is interesting where POM is not enough chemically or where PA creeps too much because of water uptake.

Machining is uncomplicated. Polyketone is turned and milled with standard carbide tools, and the material gives even chip formation and a good surface finish if the feed is kept moderate. As with all semi crystalline plastics you have to watch the internal stresses on complex geometry, because heavy heat build up in the cut can give shape deviations after machining. The rod can be bonded with the right pretreatment and can be welded with polyolefin compatible methods, but for tight chemical seals a mechanical seat is usually better.

The natural color is beige to light yellowish white, depending on supplier and thickness. The rod is made in a selection of diameters to cover common design needs, but the range is not as wide as for POM or PA. When picking diameter, allow about 1 to 2 mm of machining allowance toward the finished size, depending on the precision required.

Do you want to compare PK with POM C or PA6 C for a specific component? Send over a drawing or a short description and we will give you a recommendation.

A 3000 mm long rod in natural gives many turned wear parts from the same cut.