Sheet in POM C LM 2000x1000x30 mm white

A sheet in POM C LM gives you a self lubricating version of acetal when you need to press longer life out of dry sliding surfaces. LM stands for Low Maintenance and means the supplier has blended solid lubricants into the base resin already at extrusion, which lowers the coefficient of friction against steel by roughly 30 to 50 percent compared with pure POM C.

At heart it is the same acetal copolymer as ordinary POM C. The density is 1.41 g/cm³, the long term temperature is 105°C and the flammability rating is HB. The material takes load down to -40°C without turning brittle, which covers most of what the engineering industry needs. Water uptake is a low 0.8 percent, so parts keep their dimensions even in damp environments.

What separates the LM grade from standard POM C is the friction picture. The internal lubrication makes the material better at dry sliding applications where oil or grease cannot be used. Wear resistance rises markedly at PV values where pure acetal otherwise starts to wear quickly, and you get less stick-slip behavior at low speeds. The difference shows above all on slide plates under heavy loads, on guides in presses and on cams working against steel rollers.

In terms of color the LM grade is often blue or dark blue to tell it apart from standard acetal in the stores and in quality control. It is not a food approved material, however; for contact with food and drink you should choose POM C FG instead.

Machinability is still just as good as with pure POM C. Planing, milling and turning give fine surfaces with standard tools, and the dimensional tolerances stay stable since heat build-up is low. The lubricant in the material does not interfere with bonding or mechanical fastening; for bonded joints you should choose cyanoacrylate or polyurethane based adhesive, though, since epoxy has trouble binding to an acetal surface without pretreatment.

In practice the sheets are used for slide rails in packaging machines, wear strips in conveyors, guide plates in jigs and fixtures, plain bearings for swinging arms and cams in mechanical automation systems. The material is popular in the sawmill and steel industries as well, where boards and bars slide against fixed guides with no way to lubricate continuously.

Sheets are supplied in standard formats and can be cut to the size you want before delivery. The thickness tolerance follows DIN 16941. Remember to give the material room for temperature movement when mounting; acetal has the same thermal expansion as the other POM grades, roughly 110 to 130 micrometers per meter and degree.

A white sheet at 2000x1000x30 mm in laser markable quality, that is to say stock that can be marked with a laser for traceability on machined parts.

Do you need help choosing between POM C, POM C LM and POM CG for your application? Get in touch and we will go through the load case together.