{"id":7244,"date":"2026-04-22T08:15:00","date_gmt":"2026-04-22T08:15:00","guid":{"rendered":"https:\/\/le-creator.com\/?p=7244"},"modified":"2026-04-22T08:56:28","modified_gmt":"2026-04-22T08:56:28","slug":"types-of-peek-grades-for-different-applications","status":"publish","type":"post","link":"https:\/\/le-creator.com\/it\/blog\/types-of-peek-grades-for-different-applications\/","title":{"rendered":"Types of PEEK Grades for Different Applications [Guide]"},"content":{"rendered":"

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PEEK Grade Types: Properties, Applications, and Selection Guide<\/strong><\/p>\n

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\ud83d\udcd0 PEEK Quick Specs<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
Full Name<\/td>\nPolyether Ether Ketone (PEEK)<\/td>\n<\/tr>\n
Polymer Family<\/td>\nPolyaryletherketone (PAEK)<\/td>\n<\/tr>\n
Continuous Use Temp<\/td>\n250\u00b0C (482\u00b0F)<\/td>\n<\/tr>\n
Melting Point<\/td>\n343\u00b0C (649\u00b0F)<\/td>\n<\/tr>\n
Glass Transition<\/td>\n143\u00b0C (289\u00b0F)<\/td>\n<\/tr>\n
Density (Unfilled)<\/td>\n1.32 g\/cm\u00b3<\/td>\n<\/tr>\n
Key Standard<\/td>\nASTM D6262-23<\/a><\/td>\n<\/tr>\n
Major Producers<\/td>\nVictrex, Solvay (KetaSpire), Evonik (Vestakeep)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Selecting the appropriate grades of peek grades for specific applications is among the most important material choices an engineer will make. peek – polyether ether ketone<\/a> – is a semi-crystalline thermoplastic used in aerospace, medical, semiconductor, and Oil & Gas application. However, ‘PEEK’ is not a single material.<\/p>\n

It is available in four major grade families, each with its own set of properties, thermal characteristics, and machinability tendencies. This article describes the unfilled, glass-filled, carbon-filled, and bearing grade families of grades of peek with relevant property data, application advice, and machining tips based on manufacturing experience.<\/p>\n

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What Is PEEK and Why Does Grade Selection Matter?<\/h2>\n

\"What<\/p>\n

PEEK is a semi-crystalline thermoplastic belonging to the polyaryletherketone (PAEK) family. It holds continuous service temperatures up to 250\u00b0C (482\u00b0F), with a glass transition temperature (Tg) of 143\u00b0C (289\u00b0F) and a melting point (Tm) of 343\u00b0C (649\u00b0F). As a resin-based thermoplastic, PEEK delivers mechanical strength that rivals some metals while maintaining the processability advantages of a polymer. These thermal properties place PEEK well above standard engineering plastics like nylon (PA66, continuous 80-120\u00b0C) and even above PPS (200\u00b0C continuous).<\/p>\n

PEEK \u2014 also written as polyetheretherketone \u2014 serves demanding applications in aerospace, medical devices, semiconductor manufacturing, and oil & gas where few other plastics survive.<\/p>\n

Another characterization of PEEK is that chemical resistance. PEEK resists most organic solvents, acids, and bases. However, concentrated sulfuric acid will attack the polymer chain.<\/p>\n

This resistance renders PEEK commonly used in chemical processing, oil & gas downhole applications and semiconductor wet-bench equipment.<\/p>\n

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Why Grade Selection is important: unfilled peek cost between $40-80\/kg in industrial rod stock. Carbon-filled grades are $120-200\/kg. Medical Grade unfilled peek (per astm.org\/f2026-17<\/a>.html”>ASTM F2026-17) can be over $500\/kg.<\/p>\n

The wrong grade selection can have up to a 10 cost increase in materials alone, or lead to early end-of-life failures.<\/p>\n<\/div>\n

ASTM D8033-22<\/a> sorts literature by property specification for the peek molding and extrusion grades. ASTM D6262-23, on the other hand, is for the PAEK stock shapes – rod, plate, and tube – precursors that CNC shops machine to finished parts.<\/p>\n

Our machinists will machine all four types of the peek grade families (unfilled, glass-filled, carbon-filled and bearing grade) which all have different tooling and cutting data. The following are the properties, best-fit applications and machining characteristics of each of these grades as filed from the published data and production floor trial and error data.<\/p>\n

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Unfilled PEEK \u2014 Pure Performance for Medical and Food-Contact Applications<\/h2>\n

\"Unfilled<\/p>\n

unfilled peek, using Victrex 450G as the reference grade, provides tensile yield of 100 MPa, at break elongation of 50%, and flexural modulus of 4.1 GPa. The heat deflection temperature (HDT), i.e. the temperature where the material deforms at 264 psi (1.8 MPa) pressure, is 160C. All grades share a continuous service temperature of 250\u00b0C \u2014 one constant across the entire PEEK family.<\/p>\n

Unfilled PEEK finds its highest-value use in the medical sector. Biocompatible per ASTM F2026-17, it goes into spinal fusion cages (intervertebral spacers), dental abutments, and cranial reconstruction plates. A 2019 study in the Journal of Clinical Medicine (PMC)<\/a> confirmed PEEK as mechanically suitable for denture bases, with flexural properties meeting ISO 20795-1 requirements.<\/p>\n

In addition to its medical grades, unfilled peek can be used to deliver all FDA-compliant machinery for food processing; semiconductor wafer carriers (chemical purity is critical), and chemical-resistant valve fittings. Its 50% elongation is the highest of any peek grade, and presents excellent mechanical toughness and fatigue resistance – real benefits for impact or vibration loading situations.<\/p>\n

In machining terms, unfilled peek is the easiest to machine of the lot – others tell us that a knowledgable machinist can handle it “like nylon”; standard carbide tooling extends well, surface finish is predictable, and chip formation is clean. For machining unfilled PEEK for tight PEEK CNC machining we generally attain 0.025 mm on critical dimensions.<\/p>\n

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\ud83d\udcd0 Engineering Note<\/p>\n

ASTM F2026-17 defines implant-scale peek specifications. The price of medical-grade rodstock can be between 5 and 10 times more expensive than industrial grade ( $500\/kg versus $40-80\/kg ) with no observable material difference. Make sure of the procurement paperwork and lot history.<\/p>\n<\/div>\n

Engineers sometimes forget of the creep qualities of unfilled peek at above 150C, in the presence of sustained loads. In this upper range, it generally outdo most engineering plastics at this level of test, but it will still creep under very high sustained stress at high temperature. For static high temperature application, glass-filled and carbon-filled grades will provide greater creep performance.<\/p>\n

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Glass-Filled PEEK \u2014 Enhanced Stiffness and Dimensional Stability<\/h2>\n

\"Glass-Filled<\/p>\n

glass-filled peek has a typical 30 wt% glass fiber reinforcement present. Popular grades such as Victrex 450GL30, and Solvay KetaSpire KT-820 GF30. The addition of glass fiber raises tensile strength to 130-140 MPa (up from 100 MPa unfilled), increases flexural modulus to 6-7 GPa (4.1 GPa for unfilled is impressive), and raises HDT above 315C at 1.8 MPa.<\/p>\n

Ductility is the trade-off. Elongation at break falls from 50% to a mere 2-3%. Mishandled glass-filled peek parts are not impact-friendly, or snap-assemblyable parts requiring some flex in the design. Parts become stiffer and dimensionally stable through thermal cycles \u2014 a perfect fit for semiconductor fixturing and aerospace structural brackets.<\/p>\n

Major applications for glass-filled peek include high-temperature pump components, valve seats, mechanical seals in rotating equipment, and structural brackets in aerospace.38.<\/p>\n

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\u26a0\ufe0f Machining Warning<\/p>\n

Glass fiber renders tool life 50-70% worse than unfilled peek. Use PCD or diamond coated carbide tooling for high volume. Reduce cutting speed 30-50% below unfilled peek. glass-filled peek will also be abrasive against mating surfaces – consider this if sliding motion will occur.<\/p>\n<\/div>\n

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\u2714 When to Specify Glass-Filled Over Unfilled<\/p>\n