Torlon 4203
Torlon 4203 is Solvay's unfilled polyamide-imide (PAI) and the reference grade of the imide family, supplied as-moulded, post-cured or as machining stock.
Reference datasheet — Torlon 4203 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.
Values for the PC condition
Torlon 4203 grades and fills
Torlon 4203 is supplied in 2 conditions, soft to hard. PC is the default FabDigit quotes; the values on this page are for it.
Compare all 2 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
As-molded | Condition straight from the mold — lower strength and chemical resistance, used only for dimensional checks or as the starting point before post-curing. | 148 | 152 | 20 | 88 Shore D |
PCDefault Post-cured | Standard condition for all functional parts: multi-day stepped cure to ~260 °C that completes imidization and gives full strength, wear and chemical resistance. | 185 | 192 | 15 | 90 Shore D |
Supply forms, finishes and certifications
Ways Torlon 4203 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
STOCK | Extruded / compression-molded stock shape | Surface finish |
What is Torlon 4203?
Torlon 4203 is Solvay's unfilled polyamide-imide (PAI) and the reference grade of the imide family, supplied as-moulded, post-cured or as machining stock. It combines 192 MPa tensile strength with 15% elongation and continuous service to 260 °C, so it is used for load-bearing, wear and electrical insulating parts that outrun PEEK and PEI. The trade-offs are high cost, a mandatory multi-day post-cure, dimensional change from moisture pickup, and no weldability in the cured state. Filled grades such as 4301 or 7130 are the choice when stiffness or unlubricated wear life matters more than elongation. Torlon 4203 has a density of 1.42 g/cm³ (0.0513 lb/in³), heavier than 83% of polymer grades. Its glass-transition temperature is 275°C (527 °F). Torlon 4203 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 192 MPa (27.8 ksi) — stronger than 100% of polymer grades. Elongation at break is 15% and the elastic modulus is 4.5 GPa (0.653 Msi).
What is Torlon 4203 used for?
- compressor pistons
- thrust washers
- electrical connector insulators
- bushings and bearings
Advantages
- High strength — 185 MPa (26.8 ksi), better than 100% of polymer grades
- High service temperature — 260°C (500 °F), better than 97% of polymer grades
- Stiff — 4.5 GPa (0.653 Msi), better than 88% of polymer grades
- Good corrosion resistance — 90/100, better than 82% of polymer grades
- Tough — resists crack growth — 3.5 MPa·√m (3.19 ksi·√in), better than 81% of polymer grades
Limitations
- High embodied carbon — 16 kg CO₂/kg, worse than 98% of polymer grades
- Difficult to weld — 3/100, worse than 95% of polymer grades
- Limited formability — 5/100, worse than 95% of polymer grades
- Heavy — 1.42 g/cm³ (0.0513 lb/in³), worse than 83% of polymer grades
Torlon 4203 properties
Typical room-temperature values for Torlon 4203-PC; bars are the position among polymer grades.
Physical4
Torlon 4203 has a density of 1.42 g/cm³ (0.0513 lb/in³), heavier than 83% of polymer grades. Its glass-transition temperature is 275°C (527 °F).
Mechanical14
Torlon 4203 has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 192 MPa (27.8 ksi) — stronger than 100% of polymer grades. Elongation at break is 15% and the elastic modulus is 4.5 GPa (0.653 Msi).
Thermal10
Torlon 4203 is rated for continuous service to 260°C (500 °F). It conducts heat at 0.26 W/m·K (0.15 BTU/hr·ft·°F), better than 77% of polymer grades. Thermal expansion is 30.6 µm/m·K (17 µin/in·°F).
Electrical6
Torlon 4203 is an electrical insulator with a dielectric strength of 23.6 kV/mm (599.4 V/mil) and a resistivity of 2×10¹⁵ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 82% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of Torlon 4203 takes about 350 MJ of energy and emits 16 kg of CO₂ — more than 100% of polymer grades. Typical recycled content is 0%.
Manufacturability7
Torlon 4203's machinability is good (55/100, worse than 64% of polymer grades); weldability not recommended (3/100); formability not recommended (5/100).
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. Torlon 4203 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Torlon 4203
Is Torlon 4203 easy to machine?
Machines well but is hard and abrasive — use sharp carbide or PCD tooling, high speed, light feed, generous coolant, and expect part growth from moisture pickup after machining.
Can Torlon 4203 be welded?
Not weldable in the cured state; join with high-temperature epoxy/PAI adhesives or mechanical fasteners (avoid over-torque, use metal inserts).
Can Torlon 4203 be formed, bent or molded?
Injection mold at 345–365 °C melt with 200–230 °C molds after thorough drying (<0.05 % moisture); a stepped multi-day post-cure to ~260 °C is mandatory for full properties.
Torlon 4203 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 |
|---|---|---|
| titanium dioxidepigment / processing aid | 2 – 4 | 3 |
| PTFEinternal mold release / low-level lubricant | 0.3 – 1 | 0.5 |
| polyamide-imide (TMA/MDA based PAI)amide-imide backbone from trimellitic anhydride and aromatic diamine/diisocyanate | balance |
What surface finishes work on Torlon 4203?
Natural amber color, machined surfaces polish to a fine finish; can be plasma-treated or primed for bonding, paint/plating is uncommon and needs surface activation.
Equivalent designations
Standards and trade names that resolve to Torlon 4203 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- PAI
How much does Torlon 4203 cost?
Torlon 4203 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.
Torlon 4203 — frequently asked
What is Torlon 4203 used for?
Torlon 4203 is typically used for compressor pistons, thrust washers, electrical connector insulators and bushings and bearings. In short: reference unfilled PAI; 192 MPa unfilled strength; 260 °C continuous service.
What is the yield strength of Torlon 4203?
Torlon 4203 has a typical yield strength of 185 MPa (26.8 ksi) and a tensile strength of 192 MPa (27.8 ksi) — stronger than 100% of polymer grades. Strength varies by condition: see the 2 listed tempers.
Is Torlon 4203 easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Machines well but is hard and abrasive — use sharp carbide or PCD tooling, high speed, light feed, generous coolant, and expect part growth from moisture pickup after machining.
Can Torlon 4203 be welded?
Not readily — weldability is rated not recommended (3/100). Not weldable in the cured state; join with high-temperature epoxy/PAI adhesives or mechanical fasteners (avoid over-torque, use metal inserts).
What surface finishes work on Torlon 4203?
Natural amber color, machined surfaces polish to a fine finish; can be plasma-treated or primed for bonding, paint/plating is uncommon and needs surface activation.
Can Torlon 4203 be formed, bent or molded?
Injection mold at 345–365 °C melt with 200–230 °C molds after thorough drying (<0.05 % moisture); a stepped multi-day post-cure to ~260 °C is mandatory for full properties.
What is the maximum service temperature of Torlon 4203?
Torlon 4203 is rated for continuous use to about 260°C (500 °F), and briefly to 290°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Torlon 4203 PC and Torlon 4203 AM?
PC is the default condition — standard condition for all functional parts: multi-day stepped cure to ~260 °C that completes imidization and gives full strength, wear and chemical resistance. AM: condition straight from the mold — lower strength and chemical resistance, used only for dimensional checks or as the starting point before post-curing. Yield strength is 185 MPa in PC versus 148 MPa in AM.
How much does Torlon 4203 cost?
Torlon 4203 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
- Torlon 4203L Polyamide-imide Product Data Sheet — Solvay Specialty Polymers (2023)
- Torlon PAI Design Guide — Solvay Specialty Polymers (2022)
- TECATOR / Duratron PAI stock shape data — Ensinger / Mitsubishi Chemical Advanced Materials (2022)
- CAMPUS / UL Prospector polymer property records for PAI — CAMPUS Plastics / UL (2023)
- ASTM D638 / D790 / D256 / D648 test methods — ASTM International (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.