PCT
also Thermx
PCT is a high-heat aromatic polyester based on cyclohexanedimethanol glycol, sold as Thermx, with a higher melting point and better thermal resistance than PET or PBT.
Reference datasheet — PCT is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
PCT grades and fills
PCT is supplied in 8 conditions, soft to hard.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
15 % glass-fiber reinforced | Lower-warp reinforced grade when moderate stiffness and better surface appearance are needed. | 95 | 3.5 | ||
Glass/mineral filled, low-warp | Use where flatness and isotropic shrinkage matter more than peak strength (large flat covers, housings). | 95 | 95 | 2 | 92 HRM |
Impact-modified PCT | Pick for snap-fit or press-fit parts needing higher notched toughness at some loss of stiffness and HDT. | 105 | 105 | 3.5 | 88 HRM |
High-reflectance white LED-housing grade | TiO2-loaded, glass-reinforced white compound for LED reflector cups needing low yellowing after reflow and UV exposure. | 105 | 105 | 1.6 | 95 HRM |
30 % glass, flame-retardant UL 94 V-0 | Choose when the electrical connector or bobbin must carry a UL 94 V-0 rating at 0.4–0.8 mm wall. | 115 | 1.8 | ||
Heat-stabilized / hydrolysis-resistant grade | Long-term 150 °C air-oven ageing or humid under-hood service; adds thermal and hydrolysis stabilizers to a GF30 base. | 128 | 128 | 2.2 | 94 HRM |
30 % glass-fiber reinforced | The mainstream commercial PCT grade for SMT connectors and coil bobbins that must survive lead-free reflow. | 130 | 2.2 | 92 HRM | |
40 % glass-fiber reinforced | Maximum stiffness/strength and lowest CTE for thin-wall high-temperature structural connector bodies. | 150 | 1.8 |
Supply forms, finishes and certifications
Ways PCT is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
NATDefault | Unfilled / Natural PCT | Standard supply |
What is PCT?
PCT is a high-heat aromatic polyester based on cyclohexanedimethanol glycol, sold as Thermx, with a higher melting point and better thermal resistance than PET or PBT. Unfilled resin runs 55 MPa tensile strength, 30% elongation, 1.23 g/cm³ density and roughly 120 °C maximum service temperature, and the family covers GF15/GF30/GF40, GF30-FR, glass-mineral, impact-modified, heat-stabilized and LED-white grades for thin-wall connectors that must survive lead-free reflow. Glass-filled versions are abrasive and notch-sensitive, and the resin is not solvent-bondable in practice. PBT is the lower-cost alternative where reflow tolerance is not needed. PCT has a density of 1.23 g/cm³ (0.0444 lb/in³), heavier than 62% of polymer grades. Its glass-transition temperature is 90°C (194 °F). PCT has a yield strength of 52 MPa (7.54 ksi) and a tensile strength of 55 MPa (7.98 ksi) — stronger than 56% of polymer grades. Elongation at break is 30% and the elastic modulus is 2.1 GPa (0.305 Msi).
What is PCT used for?
- SMT/lead-free reflow connectors
- LED reflectors
- High-heat electrical components
- Specialty fiber and film
Advantages
- Low moisture uptake — 0.09%, better than 79% of polymer grades
- Good UV / weathering resistance — 55/100, better than 77% of polymer grades
Limitations
- Needs corrosion protection — 70/100, worse than 78% of polymer grades
PCT properties
Typical room-temperature values; bars are the position among polymer grades.
Physical6
PCT has a density of 1.23 g/cm³ (0.0444 lb/in³), heavier than 62% of polymer grades. Its glass-transition temperature is 90°C (194 °F).
Mechanical10
PCT has a yield strength of 52 MPa (7.54 ksi) and a tensile strength of 55 MPa (7.98 ksi) — stronger than 56% of polymer grades. Elongation at break is 30% and the elastic modulus is 2.1 GPa (0.305 Msi).
Thermal11
PCT is rated for continuous service to 130°C (266 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 68 µm/m·K (37.8 µin/in·°F).
Electrical7
PCT 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 good.
Sustainability4
Producing a kilogram of PCT takes about 100 MJ of energy and emits 4.6 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PCT's machinability is good (55/100, worse than 64% of polymer grades); weldability good (60/100); formability poor (30/100).
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. PCT is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PCT
Is PCT easy to machine?
Machinable with sharp carbide tooling and air cooling, but glass-filled grades are abrasive and notch-sensitive — generous radii and light finishing cuts.
Can PCT be welded?
Joined by ultrasonic, hot-plate, laser and vibration welding as well as heat staking; not solvent-bondable in practice, adhesives need surface pre-treatment.
Can PCT be formed, bent or molded?
Injection mold at 295–325 °C melt with 100–140 °C mold and dry the resin to <0.02 % moisture (4 h @ 120–140 °C) to avoid hydrolytic MW loss; hot runners and fast fill suit thin-wall connectors.
PCT 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 |
|---|---|---|
| terephthalic acid / DMT (terephthalate udiacid component, mol % of repeat unit | 48 – 52 | 50 |
| 1,4-cyclohexanedimethanol (CHDM)glycol component; high trans-isomer content gives the high melting point | 48 – 52 | 50 |
| glass fiberchopped E-glass in reinforced grades | 0 – 45 | 30 |
| stabilizers / nucleants / pigmentsthermal, hydrolysis and UV additive package | 0.3 – 5 | 1.5 |
What surface finishes work on PCT?
Mold-textured or gloss finishes replicate well; laser marking and pad printing are common, and reinforced grades can be electroplated only with specialty pre-treatment.
Equivalent designations
Standards and trade names that resolve to PCT in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Thermx
How much does PCT cost?
PCT is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PCT — frequently asked
What is PCT used for?
PCT is typically used for SMT/lead-free reflow connectors, LED reflectors, high-heat electrical components and specialty fiber and film. In short: reflow-tolerant polyester; higher melting than PET/PBT; thin-wall connector resin.
What is the yield strength of PCT?
PCT has a typical yield strength of 52 MPa (7.54 ksi) and a tensile strength of 55 MPa (7.98 ksi) — stronger than 56% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is PCT easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Machinable with sharp carbide tooling and air cooling, but glass-filled grades are abrasive and notch-sensitive — generous radii and light finishing cuts.
Can PCT be welded?
Yes — weldability is rated good (60/100). Joined by ultrasonic, hot-plate, laser and vibration welding as well as heat staking; not solvent-bondable in practice, adhesives need surface pre-treatment.
What surface finishes work on PCT?
Mold-textured or gloss finishes replicate well; laser marking and pad printing are common, and reinforced grades can be electroplated only with specialty pre-treatment.
Can PCT be formed, bent or molded?
Injection mold at 295–325 °C melt with 100–140 °C mold and dry the resin to <0.02 % moisture (4 h @ 120–140 °C) to avoid hydrolytic MW loss; hot runners and fast fill suit thin-wall connectors.
What is the maximum service temperature of PCT?
PCT is rated for continuous use to about 130°C (266 °F), and briefly to 260°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PCT cost?
PCT is a high-cost polymer ($$$$), pricier than about 78% 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.
Sources
- Thermx PCT high-heat polyester product data — Eastman Chemical / Celanese (2020)
- CAMPUS / Prospector thermoplastic polyester datasheets — CAMPUS Consortium / UL (2023)
- Polymer Data Handbook — poly(cyclohexylenedimethylene terephthalate) — Oxford University Press (2009)
- ISO 527 / ISO 178 / ISO 75 plastics test methods — ISO (2019)
- ASTM D638 / D790 / D648 / D256 — ASTM (2022)
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.