PET
also Arnite A, Hostadur
PET is a semi-crystalline thermoplastic polyester made from ethylene glycol and terephthalic acid, supplied as extruded rod and plate and as injection grades in unfilled, GF30, GF45, CF30, FR, solid-lubricant filled (TX), IM, FDA and rPET versions.
PET grades and fills
PET is supplied in 7 conditions, soft to hard.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Post-consumer recycled PET | Cost- and footprint-driven choice for sheet, strapping, fiber and non-critical mouldings; IV and colour vary batch to batch. | 55 | 60 | 25 | 83 Shore D |
TX | Pick for unlubricated sliding: bushings, wear pads and guides where low friction and long wear life beat maximum strength. | 60 | 6 | 83 Shore D | |
Impact-modified / toughened PET | Use when snap-fits, clips or impact-loaded housings need toughness that plain or glass-filled PET cannot supply. | 100 | 105 | 5 | 87 Shore D |
Flame-retardant UL 94 V-0 grade | Choose where a UL 94 V-0 rating at 0.8–1.6 mm is mandatory, e.g. electrical connectors, coil bobbins and switch bodies. | 135 | 2 | ||
30 % glass-fiber reinforced, heat-stabilized injection grade | Use for stiff, dimensionally stable structural mouldings needing 200 °C-class heat resistance (housings, connectors, under-hood brackets). | 160 | 2.5 | 100 HRM | |
45 % glass-fiber reinforced high-modulus grade | For maximum stiffness and creep resistance in thin-wall metal-replacement parts; brittle and abrasive to tooling. | 185 | 2 | ||
30% Carbon Fiber | PET compounded with 30 wt% chopped carbon fiber for very high stiffness, low creep, low mold shrinkage and static-dissipative/conductive behavior. | 200 | 1.8 | 100 HRM |
Supply forms, finishes and certifications
Ways PET is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FDA | Food-contact / medical compliant natural grade | Certification |
UnfilledDefault | Natural / semi-crystalline PET | Standard supply |
What is PET?
PET is a semi-crystalline thermoplastic polyester made from ethylene glycol and terephthalic acid, supplied as extruded rod and plate and as injection grades in unfilled, GF30, GF45, CF30, FR, solid-lubricant filled (TX), IM, FDA and rPET versions. Engineers choose it for high rigidity and strength, dimensional stability, low friction and wear, low moisture pickup and lower creep than POM or PA, at 1.39 g/cm3, 82 MPa tensile strength, 20 % elongation, 3.1 GPa modulus and 100 °C service, with a machinability score of 78. The limits are moderate notched impact, hydrolysis by strong alkalis and by hot water or steam above 60 °C, poor UV resistance, and the need for thorough drying before processing to prevent molecular weight loss. PET has a density of 1.39 g/cm³ (0.0502 lb/in³), heavier than 78% of polymer grades. Its glass-transition temperature is 79°C (174 °F). PET has a yield strength of 80 MPa (11.6 ksi) and a tensile strength of 82 MPa (11.9 ksi) — stronger than 88% of polymer grades. Elongation at break is 20% and the elastic modulus is 3.1 GPa (0.45 Msi).
What is PET used for?
- Precision machined mechanical components
- Slide bearings and wear strips
- Pump and valve parts
- Electronic structural parts
- Beverage bottles
- Food packaging film
- Food-contact conveyor components
Advantages
- Tough — resists crack growth — 4 MPa·√m (3.64 ksi·√in), better than 92% of polymer grades
- High strength — 80 MPa (11.6 ksi), better than 88% of polymer grades
- Low embodied carbon — 2.8 kg CO₂/kg, better than 86% of polymer grades
- Easy to machine — 78/100, better than 81% of polymer grades
Limitations
- High mold shrinkage — 2%, worse than 81% of polymer grades
- Heavy — 1.39 g/cm³ (0.0502 lb/in³), worse than 78% of polymer grades
- Needs corrosion protection — 70/100, worse than 78% of polymer grades
PET properties
Typical room-temperature values in the Unfilled condition; bars are the position among polymer grades.
Physical7
PET has a density of 1.39 g/cm³ (0.0502 lb/in³), heavier than 78% of polymer grades. Its glass-transition temperature is 79°C (174 °F).
Mechanical17
PET has a yield strength of 80 MPa (11.6 ksi) and a tensile strength of 82 MPa (11.9 ksi) — stronger than 88% of polymer grades. Elongation at break is 20% and the elastic modulus is 3.1 GPa (0.45 Msi).
Thermal11
PET is rated for continuous service to 100°C (212 °F). It conducts heat at 0.25 W/m·K (0.144 BTU/hr·ft·°F), better than 72% of polymer grades. Thermal expansion is 65 µm/m·K (36.1 µin/in·°F).
Electrical7
PET is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 78% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of PET takes about 82 MJ of energy and emits 2.8 kg of CO₂ — less than 83% of polymer grades. Typical recycled content is 25%.
Manufacturability7
PET's machinability is very good (78/100, better than 81% of polymer grades); weldability fair (45/100); formability fair (50/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. PET is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PET
Is PET easy to machine?
Machines like a free-cutting engineering plastic: sharp positive-rake carbide, high speed, light finishing passes and air/mist cooling give excellent surface finish and tight tolerances; watch for stress relief in thick stock (anneal before finish cuts).
Can PET be welded?
No solvent bonding — join by ultrasonic, hot-plate, IR or laser welding, or use cyanoacrylate/epoxy after abrasion/plasma treatment; mechanical fastening and self-tapping screws work well.
Can PET be formed, bent or molded?
Dry pellets to <0.02 % moisture (150 °C, 4 h desiccant) to avoid hydrolytic IV loss; melt 265–295 °C with hot mold 100–145 °C for full crystallization, or chilled mold/copolyester for clear amorphous APET sheet that thermoforms readily.
Manufacturability
The process limits FabDigit's quote engine applies to PET. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Excellent78 / 100 |
|---|---|
| ISO material group | N.8 |
| Cutting speed (rough / finish) | 400 / 500 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 10× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better50 / 100 |
|---|---|
| Weldability | Better45 / 100 |
Injection molding
| Mold shrinkage | 1.5 – 2.2 % |
|---|---|
| Wall thickness | 1 – 3.5 mm |
| Recommended draft | 1.5 ° |
| Pre-drying | 80 °C for 4 h |
| UV resistance | Fair |
PET chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| isophthalic acid / CHDM comonomerin bottle/APET copolyester grades to suppress crystallization | 0 – 3 | 1.5 |
| glass fiber0 in default unfilled grade; 15–45 % in GF variants | 0 – 45 | 0 |
| solid lubricant (PTFE/other)TX bearing grades | 0 – 20 | 0 |
| flame retardant + synergistFR V-0 grades | 0 – 20 | 0 |
| nucleant / heat stabilizer / mold releasstandard additive package | 0 – 3 | 0.5 |
| ethylene terephthalate repeat unit (–C10polycondensate of purified terephthalic acid (PTA) or DMT with mono-ethylene glycol; Sb/Ti/Ge catalyst residues at ppm level | balance |
What surface finishes work on PET?
Takes machining, printing, hot stamping and vacuum metallizing well after corona/flame or plasma pre-treatment; can be laser-marked, but paint adhesion needs a primer and no plating/anodizing applies.
Surface treatments FabDigit runs on polymer parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Injection Molding Coating
Organic Coating
Metallization / Functional
Equivalent designations
Standards and trade names that resolve to PET in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Arnite AHostadurMylarRynitePET-PErtalyte
- Also called
- Polyethylene TerephthalatePETE
How much does PET cost?
PET is a standard-cost polymer ($$), cheaper than about 80% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PET — frequently asked
What is PET used for?
PET is typically used for precision machined mechanical components, slide bearings and wear strips, pump and valve parts, electronic structural parts, beverage bottles and food packaging film. In short: durable industrial PET.
What is the yield strength of PET?
PET has a typical yield strength of 80 MPa (11.6 ksi) and a tensile strength of 82 MPa (11.9 ksi) — stronger than 88% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is PET easy to machine?
Yes — machinability is rated very good (78/100, better than 81% of polymer grades). Machines like a free-cutting engineering plastic: sharp positive-rake carbide, high speed, light finishing passes and air/mist cooling give excellent surface finish and tight tolerances; watch for stress relief in thick stock (anneal before finish cuts).
Can PET be welded?
With care — weldability is rated fair (45/100). No solvent bonding — join by ultrasonic, hot-plate, IR or laser welding, or use cyanoacrylate/epoxy after abrasion/plasma treatment; mechanical fastening and self-tapping screws work well.
What surface finishes work on PET?
Takes machining, printing, hot stamping and vacuum metallizing well after corona/flame or plasma pre-treatment; can be laser-marked, but paint adhesion needs a primer and no plating/anodizing applies.
Can PET be formed, bent or molded?
Dry pellets to <0.02 % moisture (150 °C, 4 h desiccant) to avoid hydrolytic IV loss; melt 265–295 °C with hot mold 100–145 °C for full crystallization, or chilled mold/copolyester for clear amorphous APET sheet that thermoforms readily.
What is the maximum service temperature of PET?
PET is rated for continuous use to about 100°C (212 °F), and briefly to 150°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PET cost?
PET is a standard-cost polymer ($$), cheaper than about 80% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in PET?
Yes — PET is available for CNC machining, sheet metal and injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Ertalyte / Ertalyte TX PET-P stock shapes datasheet — Mitsubishi Chemical Advanced Materials (Quadrant) (2022)
- Rynite PET thermoplastic polyester resin product & molding guide — DuPont / Celanese (2021)
- Arnite A (PET) grade datasheets — Envalior / DSM Engineering Materials (2023)
- CAMPUS plastics database — PET unfilled and GF grades — CWFG / CAMPUS consortium (2024)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- ASTM D5927 — Standard Specification for Thermoplastic Polyester (TPES) Molding and Extrusion Materials — ASTM (2021)
- ISO 7792-1/-2 — Plastics, thermoplastic polyester (TP) moulding and extrusion materials — ISO (2012)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.