PC-GF GF20
Reinforced grade
GF20 = 20% glass fiber reinforced
Balanced grade when GF30 warps too much but unfilled PC is too flexible.
Values for the GF20 condition
Other PC-GF grades and fills
PC-GF is listed in 7 conditions; see the grade overview at PC-GF.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
10% glass fiber reinforced | Lowest fiber loading; keeps some ductility and better surface while roughly doubling stiffness of unfilled PC. | — | 85 | 5 | 82 HRM |
Glass fiber + PTFE lubricated bearing grade | Use for gears, bushings and sliding parts where PC-GF alone squeals or wears; typically 10–20% GF with 10–15% PTFE. | — | 90 | 2.5 | 82 HRM |
UV / weather-stabilized glass-filled PC | Choose for outdoor housings, luminaires and automotive exterior brackets where unstabilized PC-GF would yellow and chalk. | — | 108 | 3 | 90 HRM |
GF20This page 20% glass fiber reinforced | Balanced grade when GF30 warps too much but unfilled PC is too flexible. | — | 110 | 3.5 | 89 HRM |
Flame-retardant glass-filled PC | Pick for electrical enclosures, EV/charger and appliance parts needing V-0 at thin wall together with GF stiffness. | — | 120 | 2.5 | — |
GF30Default 30% glass fiber reinforced | Default structural PC-GF: best stiffness/creep/dimensional stability per cost, used for housings, brackets and metal replacement. | — | 130 | 2.5 | 93 HRM |
40% glass fiber reinforced | Maximum stiffness and lowest CTE PC-GF; choose when deflection or thermal growth dominates and surface finish is unimportant. | — | 150 | 2 | 96 HRM |
What is PC-GF GF20?
PC-GF GF20 is PC-GF in the GF20 grade — balanced grade when GF30 warps too much but unfilled PC is too flexible. PC-GF GF20 has a tensile strength of 110 MPa (16 ksi), stronger than 91% of polymer grades. Elongation at break is 3.5% and the elastic modulus is 6 GPa (0.87 Msi). PC-GF GF20 has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is 147°C (297 °F). GF30 is the default condition FabDigit quotes; GF20 is available on request or by drawing note.
Advantages
- Stiff — 6 GPa (0.87 Msi), better than 89% of polymer grades
- Low, predictable mold shrinkage — 0.4%, better than 82% of polymer grades
Limitations
- Limited formability — 10/100, worse than 87% of polymer grades
- Hard to polish — 30/100, worse than 82% of polymer grades
- Limited ductility — 3.5%, worse than 79% of polymer grades
- Heavy — 1.35 g/cm³ (0.0488 lb/in³), worse than 75% of polymer grades
PC-GF GF20 properties
Typical room-temperature values for PC-GF GF20; 14 are specific to this condition. Other listed values are PC-GF reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
PC-GF GF20 has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is 147°C (297 °F).
Mechanical15
PC-GF GF20 has a tensile strength of 110 MPa (16 ksi), stronger than 91% of polymer grades. Elongation at break is 3.5% and the elastic modulus is 6 GPa (0.87 Msi).
Thermal11
PC-GF GF20 is rated for continuous service to 130°C (266 °F). It conducts heat at 0.24 W/m·K (0.139 BTU/hr·ft·°F), better than 67% of polymer grades. Thermal expansion is 30 µm/m·K (16.7 µin/in·°F).
Electrical7
PC-GF GF20 is an electrical insulator with a dielectric strength of 28 kV/mm (711.2 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (80/100), worse than 52% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of PC-GF GF20 takes about 85 MJ of energy and emits 5 kg of CO₂ — less than 79% of polymer grades. Typical recycled content is 5%.
Manufacturability8
PC-GF GF20's machinability is good (64/100, better than 63% of polymer grades); weldability good (55/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PC-GF GF20
Is PC-GF easy to machine?
Machines cleanly but glass is abrasive — use carbide or PCD tools, sharp positive rake, high speed with low feed and air cooling; avoid aggressive coolants that stress-crack PC.
Can PC-GF be welded?
Ultrasonic, vibration and hot-plate welding work but weld strength is limited by the unreinforced weld line (typically 40–60% of base strength); solvent bonding is risky due to stress cracking.
Can PC-GF be formed, bent or molded?
Injection mold only; dry 4 h at 120 °C to <0.02% moisture, melt 285–320 °C, mold 80–120 °C, wear-resistant screw/nozzle, and design for anisotropic shrink (0.2–0.5%) to control warp.
What surface finishes work on PC-GF?
Fiber read-through dulls the surface — texture, paint or hard-coat rather than polish; PC-GF takes primer/paint and vacuum metallizing well and can be laser-marked.
PC-GF 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 |
|---|---|---|
| glass fiberchopped E-glass, silane sized for PC coupling | 10 – 40 | 30 |
| additivesheat stabilizer, mold release, pigment; FR/UV packages in modified grades | 0.3 – 2 | 1 |
| bisphenol-A polycarbonatematrix resin | ≥ 55 (balance) | — |
PC-GF GF20 — frequently asked
What is PC-GF GF20 used for?
PC-GF GF20 is typically used for structural housings, electrical connectors, automotive brackets and power tool bodies. In short: stiffest polycarbonate variant; low-creep structural PC; opaque, abrasive to tooling.
What is the tensile strength of PC-GF GF20?
PC-GF GF20 has a typical tensile strength of 110 MPa (16 ksi) — stronger than 91% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is PC-GF GF20 easy to machine?
Reasonably — machinability is rated good (64/100, better than 63% of polymer grades). Machines cleanly but glass is abrasive — use carbide or PCD tools, sharp positive rake, high speed with low feed and air cooling; avoid aggressive coolants that stress-crack PC.
Can PC-GF GF20 be welded?
Yes — weldability is rated good (55/100). Ultrasonic, vibration and hot-plate welding work but weld strength is limited by the unreinforced weld line (typically 40–60% of base strength); solvent bonding is risky due to stress cracking.
What surface finishes work on PC-GF GF20?
Fiber read-through dulls the surface — texture, paint or hard-coat rather than polish; PC-GF takes primer/paint and vacuum metallizing well and can be laser-marked.
Can PC-GF GF20 be formed, bent or molded?
Injection mold only; dry 4 h at 120 °C to <0.02% moisture, melt 285–320 °C, mold 80–120 °C, wear-resistant screw/nozzle, and design for anisotropic shrink (0.2–0.5%) to control warp.
What is the maximum service temperature of PC-GF GF20?
PC-GF GF20 is rated for continuous use to about 130°C (266 °F), and briefly to 160°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D3935 — Standard Classification System for Polycarbonate (PC) Unfilled and Reinforced Material — ASTM International (2017)
- ISO 7391-2 — Plastics: Polycarbonate moulding and extrusion materials, Part 2: Preparation of test specimens and determination of properties — ISO (2022)
- Makrolon glass-fibre reinforced grades (e.g. 8035, 8345) datasheets — Covestro (2023)
- LEXAN 3412/3413 glass-filled PC resin datasheets — SABIC (2022)
- CAMPUS plastics database — PC-GF ISO datasets — CWFG/CAMPUS consortium (2024)
- Engineering Plastics Handbook / Granta polymer property ranges — McGraw-Hill / Ansys Granta (2021)
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.