PCT IM (Impact-modified PCT)
Grade
also Thermx
Pick for snap-fit or press-fit parts needing higher notched toughness at some loss of stiffness and HDT.
Values for the IM 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 |
IMThis page 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 | — |
What is PCT IM?
PCT IM is PCT in the IM grade — pick for snap-fit or press-fit parts needing higher notched toughness at some loss of stiffness and HDT. PCT IM has a yield strength of 105 MPa (15.2 ksi) and a tensile strength of 105 MPa (15.2 ksi) — stronger than 97% of polymer grades. Elongation at break is 3.5% and the elastic modulus is 8 GPa (1.16 Msi). PCT IM has a density of 1.42 g/cm³ (0.0513 lb/in³), heavier than 83% of polymer grades. Its glass-transition temperature is 90°C (194 °F).
Advantages
- High strength — 105 MPa (15.2 ksi), better than 97% of polymer grades
- Stiff — 8 GPa (1.16 Msi), better than 91% of polymer grades
- Low, predictable mold shrinkage — 0.35%, better than 86% of polymer grades
- Conducts heat well — 0.29 W/m·K (0.168 BTU/hr·ft·°F), better than 80% of polymer grades
- High service temperature — 150°C (302 °F), better than 79% of polymer grades
Limitations
- Limited formability — 6/100, worse than 91% of polymer grades
- Heavy — 1.42 g/cm³ (0.0513 lb/in³), worse than 83% of polymer grades
- Difficult to machine — 40/100, worse than 82% of polymer grades
- Limited ductility — 3.5%, worse than 79% of polymer grades
- Needs corrosion protection — 70/100, worse than 78% of polymer grades
PCT IM properties
Typical room-temperature values for PCT IM; 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 IM has a density of 1.42 g/cm³ (0.0513 lb/in³), heavier than 83% of polymer grades. Its glass-transition temperature is 90°C (194 °F).
Mechanical10
PCT IM has a yield strength of 105 MPa (15.2 ksi) and a tensile strength of 105 MPa (15.2 ksi) — stronger than 97% of polymer grades. Elongation at break is 3.5% and the elastic modulus is 8 GPa (1.16 Msi).
Thermal11
PCT IM is rated for continuous service to 150°C (302 °F). It conducts heat at 0.29 W/m·K (0.168 BTU/hr·ft·°F), better than 80% of polymer grades. Thermal expansion is 68 µm/m·K (37.8 µin/in·°F).
Electrical7
PCT IM 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 IM 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 IM's machinability is fair (40/100, worse than 82% of polymer grades); weldability poor (20/100); formability not recommended (6/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PCT IM
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 IM — frequently asked
What is PCT IM used for?
PCT IM 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 IM?
PCT IM has a typical yield strength of 105 MPa (15.2 ksi) and a tensile strength of 105 MPa (15.2 ksi) — stronger than 97% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is PCT IM easy to machine?
Not especially — machinability is rated fair (40/100, worse than 82% 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 IM 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 IM?
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 IM 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 IM?
PCT IM is rated for continuous use to about 150°C (302 °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.