PET (Ertalyte) Material — Bearing-Grade Sheet, Rod & Tube

Ertalyte is Mitsubishi Chemical Advanced Materials' (formerly Quadrant) trade name for bearing- and wear-grade polyethylene terephthalate (PET-P) stock shapes. Unlike the amorphous, glycol-modified PETG used in displays and thermoforming, Ertalyte is semi-crystalline, opaque, and engineered specifically for precision machined parts operating in sliding, rotating, and food-contact environments. It is not the same material as PETG, and the two should never be substituted for one another in engineering drawings.

At a glance:

• Semi-crystalline PET-P (polycondensate); not glycol-modified
• Continuous use temperature: 212°F (100°C); HDT at 264 psi: ~185°F (85°C)
• Tensile strength: 11,600 psi; flexural modulus: 600,000 psi
• Very low coefficient of friction; superior wear vs. acetal in wet/lubricated conditions
• FDA 21 CFR 177.1630 compliant — suitable for direct food-contact
• Available in natural (translucent white/off-white) and Ertalyte TX (PTFE + solid lubricant)
• Forms: sheet, rod, tube in standard and custom sizes

What Is Ertalyte PET-P and Why Does It Matter?

PET-P (PET polycondensate) is a semi-crystalline version of polyethylene terephthalate produced by solid-state polymerization to a higher molecular weight than bottle-grade PET. The higher molecular weight, combined with controlled crystallization during extrusion, produces a material with excellent dimensional stability, low moisture absorption (0.10% at 24 hr vs. 1.5–4.5% for nylon 6/6), and a hard, slick surface that resists wear in sliding applications.

Ertalyte is Quadrant/Mitsubishi's branded PET-P. Within the stock-shape market, "Ertalyte" has become the dominant name for bearing-grade PET, analogous to how "Delrin" stands in for acetal homopolymer. Generic PET-P is also available from other compounders, but Ertalyte remains the performance benchmark.

Why Engineers Choose Ertalyte Over Acetal

Acetal (Delrin) is the classic bearing plastic. Ertalyte enters the picture when:

• Wet environments: Ertalyte maintains its dimensions and wear rate in water or process fluids because it absorbs only 0.10% moisture. Acetal absorbs 0.22–0.25% in 24 hr and swells measurably in sustained water immersion.
• Food and beverage processing: FDA 21 CFR 177.1630 compliance plus extremely low moisture uptake means Ertalyte parts maintain tight tolerances in wash-down environments.
• Sustained bearing loads: Ertalyte's compressive strength (15,000 psi) and creep resistance under sustained load outperform standard acetal in heavy-load bushing applications.
• Chemical resistance: Ertalyte resists a wider range of dilute acids than acetal and shows better performance in weak organic acids common in food processing.

For a full side-by-side breakdown, see the PET vs acetal comparison or the PET vs PETG comparison.

PET Material Properties

Ertalyte's mechanical profile combines high stiffness, excellent compressive strength, and low creep — a combination driven by its semi-crystalline structure. The crystalline fraction locks in dimensional stability even when the surrounding amorphous regions soften with heat.

Mechanical Properties (Ertalyte, 73°F)

Thermal Properties

Electrical and Physical Properties

Ertalyte is a good electrical insulator with volume resistivity of approximately 10¹⁵ Ω·cm — useful for applications requiring both wear resistance and electrical isolation. Density is 1.41 g/cc, slightly heavier than acetal (1.41) but much lighter than metal bearings. Water absorption at saturation is only 0.26%, giving Ertalyte outstanding dimensional stability in humid or wet-running environments.

For the complete datasheet including Ertalyte TX values, see PET properties.

Ertalyte Grades

Ertalyte (Natural)

The base grade: unfilled, semi-crystalline PET-P in natural off-white/translucent color. This is the most widely stocked grade for general-purpose bearings, bushings, wear strips, and food-zone components. Full FDA 21 CFR 177.1630 compliance.

Ertalyte TX

Ertalyte TX is the lubricated wear-grade: PET-P compounded with PTFE and a proprietary solid lubricant. The PTFE reduces the coefficient of friction significantly — from ~0.25 (dry vs. steel) for unfilled Ertalyte to ~0.10 for TX. This translates to lower wear rates in high-load, low-speed bearing and bushing applications where external lubrication is impractical.

When to choose TX:

• Dry-running bearings and bushings where re-lubrication is impossible or impractical
• Food and pharmaceutical machinery where lubricant contamination must be eliminated
• Applications requiring quieter operation and reduced stick-slip

Ertalyte TX is also FDA compliant. It has an opaque white appearance compared to the slightly translucent natural Ertalyte.

Generic PET-P

Several compounders offer generic bearing-grade PET-P meeting the same ASTM requirements. Properties are comparable to Ertalyte natural; the primary difference is lot traceability and brand recognition in some specifications. See the PET grades page for a full comparison including "Ertalyte TX" (vol 150).

PET Stock Shapes and Sizes

FedMat stocks Ertalyte in three standard forms:

PET Sheet

Available in thicknesses from 0.25" to 4.0" and standard sheet sizes of 24" × 48". Ertalyte sheet is commonly machined into wear strips, pads, slides, and flanged components. For size availability and tolerances, see the PET sheet page.

PET Rod

Diameters from 0.500" through 6.0" in 4-ft lengths. Ertalyte rod is the primary form for turned bearings, bushings, and rollers. For stocking details and size tolerances, see the PET rod page.

PET Tube

OD up to 6.0", various ID/wall combinations. Tube minimizes material removal when machining bearing bores to final diameter. Available in Ertalyte natural; TX grades in tube form are less commonly stocked — confirm availability.

Applications

Ertalyte excels in applications where acetal can no longer handle the moisture, load, or hygienic requirements:

Bearings and bushings — The primary application. Ertalyte outperforms acetal and nylon in wet-running bushings in food processing equipment, where wash-down conditions degrade nylon dimensionally and acetal can exhibit marginal corrosion resistance to cleaning agents.

Wear strips and slide rails — Conveyors and packaging machinery use Ertalyte wear strips because they maintain tight thickness tolerances in humid ambient conditions.

Food-contact components — FDA compliance, low moisture absorption, and resistance to weak acids (vinegar, citric acid) make Ertalyte a standard choice for manifolds, pump bodies, valve seats, and guides in food and beverage plants.

Rollers and sheaves — Ertalyte rollers run quietly against metal shafts with less squeaking and lower wear than unfilled nylon.

Medical device trays and fixtures — The low moisture uptake and FDA status suit clean-room part trays and assembly fixtures.

For detailed use-case guidance, see PET applications.

Machining Ertalyte

Ertalyte machines on standard CNC equipment with carbide or HSS tooling. Key parameters:

• Turning: 400–600 SFM surface speed; feed 0.005–0.010 IPR; positive-rake sharp carbide
• Milling: 200–400 SFM; 0.003–0.006 IPT chip load
• Drilling: Parabolic flute drills; 150–250 SFM; standard lip angles
• Tapping: Spiral flute taps; cutting fluid recommended; standard helicoil inserts hold well

Ertalyte generates long stringy chips less than acetal; chip breaking and chip evacuation matter for deep holes. No pre-drying required before machining — moisture absorption is too low to cause issues. For Ertalyte TX, wear is slightly greater on carbide tooling due to the PTFE filler — expect shorter insert life at equal surface speeds. Full machining parameters and setup guidance are in the PET machining guide.

FDA and Food-Grade Compliance

Ertalyte (PET-P) meets FDA 21 CFR 177.1630 (polyethylene terephthalate — homopolymer and copolymer resins). Ertalyte TX also carries this compliance. Both grades are suitable for repeated direct food contact. USDA (Agriculture) approval for incidental food contact in meat and poultry plants adds further credibility.

For full compliance detail including USDA and REACH status, see PET FDA and food-grade compliance.

Specifications and Standards

Ertalyte stock shapes are produced per ASTM D7292 (polyethylene terephthalate — PET — extruded shapes). Dimensional tolerances follow manufacturer published tables. Some military and DoD specifications reference "PET-P" or cite Quadrant/Mitsubishi Ertalyte by name. For specific ASTM test method references and size tolerance tables, see PET specifications.

Cost and Sourcing

Ertalyte is priced modestly above acetal, reflecting the tighter process control required for semi-crystalline extrusion. At small quantities, a 1" diameter rod will run approximately 30–60% more per foot than equivalent Delrin. The cost premium disappears quickly in any application where acetal's moisture swelling or lower wear resistance leads to more frequent part replacement.

Against nylon (PA6/6), Ertalyte is roughly comparable in cost but delivers far better dimensional stability in wet environments. For applications where moisture stability is the governing requirement, the case for Ertalyte over nylon is strong.

More related guides

Applications

• Bushings & Bearings
• Wear Strips & Slides
• Food Processing Components

Industries

• Food & Beverage
• Packaging

Compare to other materials

• PET vs. PETG
• PET vs. Acetal (Delrin)
• PET vs. Nylon

Frequently asked questions — PET FAQ