Hollow Bar in PEEK+PTFE 3000 mm blue

A hollow bar in PEEK+PTFE is a semi-finished product for you who turn bushings, plain bearings, piston rings or seals at component size. You save turning work compared with solid round rod, and the waste is smaller when the inner diameter already sits close to the finished dimension.

The material combines the mechanics of the PEEK matrix with PTFE blended in as a lubricant in the structure. The result is a plastic that handles 260 degrees continuously and 300 degrees short term, while sliding contacts against metal keep low friction even without external lubrication. The tensile strength sits around 96 MPa per ISO 527, the ball indentation hardness at 205 MPa. The flammability rating is V0. The density is 1.35 g/cm³, the water uptake negligible at 0.03 percent, which keeps the dimensions stable even in damp operation.

Chemically the material handles in principle everything ordinary PEEK handles: strong acids, bases, hydraulic fluids, fuels and most solvents. The PTFE content does not affect that part noticeably. The dry running properties, on the other hand, improve markedly, which makes it a relevant choice for plain bearings where a lubricant is not wanted or not possible, for example in food machinery, vacuum chambers or cleanroom equipment.

Typical parts turned from a PEEK+PTFE hollow bar are slide bushings in pumps and compressors, valve guides, piston rings in reciprocating compressors for dry gases, seals at high temperatures, shaft seals and wear rings. The material is popular in the semiconductor industry too and in medical technology where sterilization cycles with hot steam are an everyday matter.

For machining the same principles apply as for other PEEK: sharp carbide inserts, proper cooling to keep the temperature down in the cut, and a careful feed at finishing so that the surface does not go fuzzy from exposed PTFE. Better to warm the material gently before machining if you work in a cold workshop climate; it lowers the risk of stresses in the surface.

Remember that the PTFE addition lowers the absolute strength somewhat compared with pure PEEK. If the part is to carry a high point load or be exposed to large tensile stresses, pure PEEK or PEEK CF30 is the better choice. If the part is going to slide against metal, preferably without a lubricant, PEEK+PTFE is usually far ahead.

The hollow bars are supplied with the inner diameter, outer diameter and length matched to your need. We cut to the length you want and can quote fixed lengths or dimensions from a drawing. Get in touch with the outer and inner dimensions of the part and we will come back with the right blank.