Sheet in PEEK MG 1000x500x25 mm blue

PEEK MG belongs to the lubricant modified PEEK grades. The base resin is PEEK, and a blend of carbon, graphite and PTFE has been baked into the polymer to work as a built in dry lubricant. The result is a sheet that combines the temperature resistance and chemical resistance of the PEEK base with a clearly lower coefficient of friction against metal surfaces than pure PEEK. The difference usually shows on the very first test run of the sliding pair: the mating part heats up less and wear on the PEEK part is measurably lower over long test intervals.

In sheet format the material is used when you mill out slide plates, guide strips, wear rails and flat bearing elements. The sheet is also a good choice for slide guides in conveyors, lifting cylinders and packaging machines that run hot. In operation without lubricant PEEK MG handles surprisingly high PV values, because the built in lubricant is fed out over time. That means a sliding pair that cannot be lubricated regularly still lasts a long time. Other typical uses are compressor parts, valve seats and sealing elements where a metal mating part works against the plastic surface continuously under pressure and temperature.

The temperature is PEEK typical: 260 degrees long term and 300 degrees short term. Density sits around 1.31 g/cm³, water absorption is 0.03 percent and the fire rating is V-0 without added flame retardants. The mechanical core figures are a tensile strength in the region of 116 MPa and a ball indentation hardness of 253 N/mm² on the PEEK base; the lubricant additive lowers the tensile strength by a percent or so and raises the wear resistance considerably. Notched impact strength and impact strength are good but not the highest in the PEEK family, so avoid sharp corners at heavy tonnage. Thermal conductivity of 0.27 W/(m·K) means local hot spots in the sliding contact conduct away slowly, so keep that in mind when dimensioning for heat.

Chemically PEEK MG handles the same media as pure PEEK: oils, solvents, hydraulic fluids, alkaline and weakly acidic environments, hot water and steam. Concentrated sulfuric acid and nitrate solutions are borderline cases. The material also takes constant heat cycling without losing dimensional stability, which is valuable in oven equipment and pump housings. Resistance to radiation is good, which makes PEEK MG useful in sterilized parts in healthcare and laboratory environments where the cycles are repeated countless times. For food contact and pharmaceutical applications the general approvals of many grades give a good starting point, but always check the specific certificates your application requires.

Machinability is good. Milling and planing work with sharp carbide tools, and plenty of coolant helps keep the heat in the chip as the work continues. When drilling, go slowly with good flushing and you avoid burn marks in the hole walls. Annealing before final machining is recommended for tight tolerances. The sheet can be bonded and can be hard to joint glue without plasma pretreatment, but mechanical joints with M screws or inserts work well. For larger parts that are to be machined symmetrically it is smart to mill the part from both sides in even layers, so the remaining stresses in the sheet do not deform the finished part once the chips come off. When milling many small identical parts out of one large square in the sheet, it pays to mill the whole run in several shallow passes rather than a few deep ones, because the heat then has time to conduct away between passes and the final surface comes out better.

Standard thicknesses start around 8 mm and go up to 80 mm. The natural color is dark gray to black depending on the graphite and carbon content. If you need other formats or cut blanks, we help with the cutting. The sheet can also be planed down to thinner thicknesses from a standard size, which is sometimes faster than waiting for a dimension we do not stock. Choosing between PEEK MG, PEEK MD or pure PEEK comes down to operating temperature, the mating part and whether the part runs lubricated or dry.

Another common question when choosing a sheet is whether the CF30 version (carbon fiber reinforced) or unreinforced PEEK MG fits best. In most slide plate applications unreinforced PEEK MG goes a very long way, and it is when dimensional stability under constant load or a large temperature jump becomes decisive that CF30 deserves consideration. Likewise, if you are milling out parts with narrow web sections or overhanging sections that have to hold their dimensions during machining and operation, CF30 is the safer route. The standard choice for a broader set of guide strips and slide guides is still unreinforced PEEK MG, both for price and for machinability.

The blue MG sheet with 25 mm of stock in 1000 x 500 mm is medical quality that takes steam sterilization, and the blue shade is often used to color code instrument parts.

Get in touch and we will give you a straight recommendation based on your application.