PCT HS
Additive grade
also Thermx
HS = 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.
Values for the HS condition
Other PCT grades and fills
PCT is listed in 8 conditions; see the grade overview at PCT.
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 | — |
HSThis page 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 | — |
What is PCT HS?
PCT HS is PCT in the HS grade — long-term 150 °C air-oven ageing or humid under-hood service; adds thermal and hydrolysis stabilizers to a GF30 base. PCT HS has a yield strength of 128 MPa (18.6 ksi) and a tensile strength of 128 MPa (18.6 ksi) — stronger than 99% of polymer grades. Elongation at break is 2.2% and the elastic modulus is 9.5 GPa (1.38 Msi). PCT HS has a density of 1.47 g/cm³ (0.0531 lb/in³), heavier than 86% of polymer grades. Its glass-transition temperature is 90°C (194 °F).
Advantages
- High strength — 128 MPa (18.6 ksi), better than 99% of polymer grades
- Stiff — 9.5 GPa (1.38 Msi), better than 94% of polymer grades
- Low, predictable mold shrinkage — 0.25%, better than 93% of polymer grades
- Conducts heat well — 0.3 W/m·K (0.173 BTU/hr·ft·°F), better than 83% of polymer grades
- High service temperature — 160°C (320 °F), better than 81% of polymer grades
Limitations
- Limited formability — 4/100, worse than 98% of polymer grades
- Limited ductility — 2.2%, worse than 92% of polymer grades
- Heavy — 1.47 g/cm³ (0.0531 lb/in³), worse than 86% of polymer grades
- Difficult to machine — 35/100, worse than 84% of polymer grades
PCT HS properties
Typical room-temperature values for PCT HS; 25 are specific to this condition. Other listed values are PCT reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
PCT HS has a density of 1.47 g/cm³ (0.0531 lb/in³), heavier than 86% of polymer grades. Its glass-transition temperature is 90°C (194 °F).
Mechanical10
PCT HS has a yield strength of 128 MPa (18.6 ksi) and a tensile strength of 128 MPa (18.6 ksi) — stronger than 99% of polymer grades. Elongation at break is 2.2% and the elastic modulus is 9.5 GPa (1.38 Msi).
Thermal11
PCT HS is rated for continuous service to 160°C (320 °F). It conducts heat at 0.3 W/m·K (0.173 BTU/hr·ft·°F), better than 83% of polymer grades. Thermal expansion is 68 µm/m·K (37.8 µin/in·°F).
Electrical7
PCT HS 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 (75/100), worse than 66% of polymer grades. UV resistance is good.
Sustainability4
Producing a kilogram of PCT HS 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 HS's machinability is fair (35/100, worse than 84% of polymer grades); weldability poor (20/100); formability not recommended (4/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PCT HS
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.
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.
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 |
PCT HS — frequently asked
What is PCT HS used for?
PCT HS 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 HS?
PCT HS has a typical yield strength of 128 MPa (18.6 ksi) and a tensile strength of 128 MPa (18.6 ksi) — stronger than 99% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is PCT HS easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% 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 HS be welded?
Not readily — weldability is rated poor (20/100). 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 HS?
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 HS 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 HS?
PCT HS is rated for continuous use to about 160°C (320 °F), and briefly to 260°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.