Hollow Bar in PEEK Mod 3000 mm black

PEEK Mod is a modified PEEK grade where additives lower the friction and raise the wear resistance compared with pure PEEK. The hollow bar is the format you choose when the part is to be turned from a tubular blank, typically plain bearing sleeves, bushings and cylindrical wear components.

PEEK as a base material belongs to the high performance class. The operating range is continuous up to about 260 degrees, and short term exposure handles 300 degrees. The flammability rating is V0 without dripping melt. The specific density of the Mod grade sits around 1.44 g/cm3. Tensile strength per ISO 527 sits around 84 MPa, ball indentation hardness around 250 MPa. The thermal conductivity is about 0.82 W/mK, which is high for an unreinforced engineering plastic and helps carry heat away when friction is generated in a bearing.

Chemical resistance. PEEK stands up to most organic solvents, acids and bases in moderate concentrations, plus a broad category of industrial fluids. The Mod additives as a rule do not affect the chemical resistance of the base material.

What makes the Mod grade different? The modification is formulated to lower the sliding friction and improve the wear surface against metallic mating parts. Pure PEEK works mechanically but has relatively high friction against steel without lubrication. The Mod grade is therefore a natural choice for dry bearings, bearings with marginal lubrication or where the process does not allow oil and grease.

The water uptake is negligible, which means the dimensions do not wander between a dry and a damp environment. Through temperature swings PEEK is noticeably dimensionally stable.

Typical uses for a hollow bar in PEEK Mod:

plain bearing sleeves in pumps, valves and compressors

bushings in robot and machine joints

guide pulleys and rollers in high temperature environments

wear shims in the textile and paper industry

special parts in chemical process equipment where metal cannot take the medium

Machining. PEEK turns, drills and mills very well in ordinary workshop machines. The hollow bar is a preselected geometry for turning, which saves material and time compared with turning from round rod. Sharp inserts in carbide or coated HSS, high cutting speed, moderate feed. Heat removal during machining is worth thinking about at deep cuts; the material is heat sensitive during machining despite the high operating temperature range.

Bonding does not work without surface pretreatment. Mechanical fastening, press fitting or threading are the standard routes.

Choosing between PEEK grades. Pure PEEK is the first choice for structural components where friction is not the primary function. PEEK Mod when the plain bearing is the whole point. PEEK GF30 or CF30 for higher stiffness and creep margin. PEEK HT for extra temperature margin.

We cut the hollow bars to your dimensions. Standard dimensions are in the range, special dimensions are arranged on request.

Need a sounding board on grade, speed and pV value for your bearing case? Send over the operating conditions and we will come back with a recommendation.