Hollow Bar in POM C FG 1000 mm natural

A hollow bar in POM C FG gives you a food approved start on the turning job. You avoid coring out a solid rod, which cuts the machining time and brings the material cost for bushings, sleeves and thin rings down considerably.

POM C is an acetal copolymer known for dimensional stability, low friction and good wear resistance. The density sits at 1.41 g/cm³. The long-term temperature is 105°C and for short periods it takes load down toward -40°C, which covers most of the cold room and warm room environments in the food industry. The flammability rating is HB and the water uptake lands around 0.8 percent, so parts keep their dimensions even in damp production environments.

The FG grade is approved for direct food contact under EU regulation 10/2011 and FDA 21 CFR 177.2470. It is the same copolymer as ordinary POM C underneath, but with pigmentation and additives that meet the migration requirements. The natural color is white or bone white. Many customers choose a blue FG grade to make visual detection easier if something breaks in an open process, and that variant can be ordered as well.

Acetal has low friction against steel and against itself, which makes the material a standard item for plain bearings, guides and rollers in filling and conveyor lines. The chemical resistance is enough against common cleaning agents, mild alkali and most solvents used in CIP cleaning. Strong acids and oxidizing chemicals are not the strength of the material, so for aggressive environments PEEK FG or PVDF is more relevant.

Machinability is one of the big reasons turners appreciate acetal. The chip breaks in a controlled way, the surface finish comes out high even with simple tool bits, and the dimensional tolerances stay stable because the heat build-up is low. The hollow bar cuts the setup time further; you chuck straight on the surface and can start on the inside without pre-drilling.

Typical parts turned from this kind of blank are bushings in filling machines, slide rings in conveyors, spacer tubes for dosing equipment and wear parts in packaging machines for dairy, meat processing and brewing. Smaller gears, cams and guide studs suit it well too, since POM C does not crack at a notch and has good fatigue strength.

Hollow bars are supplied with an outer and inner diameter plus a length that leaves working allowance for facing and cutting. Remember to specify the tolerance on OD and ID when you order; the standard tolerance follows DIN 16941 but tighter dimensions can be quoted. When machining: cool with compressed air or emulsion, but avoid chlorinated coolants. The material is hygroscopic at a low level, so let the bars acclimatize in the workshop before you start turning to tight tolerances.

The 1000 mm hollow bar in natural is approved for direct food contact and suits sleeves and rings turned for food machinery.

Need help choosing the right FG grade or dimension for your job? Get in touch and we will go through the tolerance requirement together.