PETG-CF
also CF PETG, PETG CF
PETG-CF is glycol-modified PET copolyester (PETG) compounded with 10–30 wt% chopped/milled carbon fiber, sold almost exclusively as 3D-printing filament (and some pellet).
Values for the CF20 condition
PETG-CF grades and fills
PETG-CF is supplied in 5 conditions, soft to hard. CF20 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
RPETG-CF | Cost- and footprint-driven choice for non-critical prints; expect wider batch-to-batch spread in strength, colour and diameter. | 43 | 45 | 3.5 | 78 Shore D |
Static-dissipative PETG-CF | Use for electronics trays, ATE fixtures and cleanroom tooling where surface resistivity must sit in the 10^6–10^9 Ω dissipative window. | 46 | 48 | 3 | 79 Shore D |
~5–10 wt% carbon fiber | Pick when you want the matte CF look and reduced warping but need more ductility and gentler nozzle wear. | 48 | 9 | ||
CF20Default ~15–20 wt% chopped carbon fiber | Default commercial PETG-CF filament: best balance of stiffness, matte finish and printability on a hardened 0.4–0.6 mm nozzle. | 52 | 4.5 | ||
~25–30 wt% carbon fiber | Choose for maximum stiffness and dimensional stability in jigs, fixtures and drone/RC frames; accept brittle behaviour and fast nozzle wear. | 56 | 2.2 |
What is PETG-CF?
PETG-CF is glycol-modified PET copolyester (PETG) compounded with 10–30 wt% chopped/milled carbon fiber, sold almost exclusively as 3D-printing filament (and some pellet). The fiber roughly doubles stiffness, suppresses warping and stringing, and gives a matte black surface with much better dimensional stability than neat PETG, while keeping PETG's easy, low-odour, non-hygroscopic printing behaviour. Limits: it is amorphous, so the useful service ceiling stays near the ~78 °C Tg; elongation and notched impact drop sharply versus neat PETG, the compound is abrasive (hardened nozzle required), and interlayer strength remains the weakest direction of any printed part. PETG-CF has a density of 1.32 g/cm³ (0.0477 lb/in³), heavier than 72% of polymer grades. Its glass-transition temperature is 79°C (174 °F). PETG-CF has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 52 MPa (7.54 ksi) — stronger than 52% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 4.2 GPa (0.609 Msi).
What is PETG-CF used for?
- Functional brackets
- Enclosures
- Tooling
Advantages
- Low, predictable mold shrinkage — 0.3%, better than 90% of polymer grades
- Stiff — 4.2 GPa (0.609 Msi), better than 87% of polymer grades
- Conducts heat well — 0.3 W/m·K (0.173 BTU/hr·ft·°F), better than 83% of polymer grades
Limitations
- Hard to polish — 30/100, worse than 82% of polymer grades
- Limited service temperature — 68°C (154 °F), worse than 80% of polymer grades
- High embodied carbon — 7 kg CO₂/kg, worse than 77% of polymer grades
- Limited ductility — 4.5%, worse than 75% of polymer grades
PETG-CF properties
Typical room-temperature values for PETG-CF-CF20; bars are the position among polymer grades.
Physical4
PETG-CF has a density of 1.32 g/cm³ (0.0477 lb/in³), heavier than 72% of polymer grades. Its glass-transition temperature is 79°C (174 °F).
Mechanical13
PETG-CF has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 52 MPa (7.54 ksi) — stronger than 52% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 4.2 GPa (0.609 Msi).
Thermal11
PETG-CF is rated for continuous service to 68°C (154 °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 40 µm/m·K (22.2 µin/in·°F).
Electrical2
Chemical & Environmental3
Corrosion resistance is very good (78/100), worse than 61% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of PETG-CF takes about 110 MJ of energy and emits 7 kg of CO₂ — more than 64% of polymer grades. Typical recycled content is 5%.
Manufacturability8
PETG-CF's machinability is good (62/100, better than 60% of polymer grades); weldability fair (45/100); formability poor (25/100).
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. PETG-CF is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PETG-CF
Is PETG-CF easy to machine?
Drills, mills and taps easily at high speed with sharp carbide and light feeds; carbon fiber is abrasive and dust should be extracted, and keep tools cool to avoid smearing near Tg.
Can PETG-CF be welded?
Hot-plate, hot-gas and ultrasonic welding work on the matrix but fiber at the joint cuts strength; solvent/adhesive bonding needs sanding plus cyanoacrylate or epoxy since PETG resists most solvents.
Can PETG-CF be formed, bent or molded?
Print at 240–260 °C nozzle / 70–85 °C bed with a hardened steel or ruby nozzle ≥0.4 mm, dry the filament 4–6 h at 65 °C, and use slow first layers and generous cooling; injection molding requires drying and low shear to preserve fiber length.
Manufacturability
The process limits FabDigit's quote engine applies to PETG-CF. Design inside these and the part quotes instantly; outside them it routes to an engineer.
3D printing
| Technologies | FDM |
|---|---|
| Layer height | 50 – 300 µmdefault 100 µm |
| Minimum wall / feature | 1 / 0.5 mm |
| Build envelope | 300 × 300 × 380 mm |
| Supports | Yes |
| Anisotropy | Moderate |
PETG-CF 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 |
|---|---|---|
| carbon fiber (chopped/milled PAN-based)primary reinforcement; sets stiffness and abrasiveness | 5 – 30 | 18 |
| processing aids / lubricants / pigmentdispersants, chain extenders, carbon black for colour | 0.5 – 3 | 1.5 |
| PETG (glycol-modified PET copolyester, Camorphous copolyester matrix | ≥ 70 (balance) |
What surface finishes work on PETG-CF?
Comes out matte black and hides layer lines well; sand or bead-blast for uniformity, avoid solvent vapor smoothing (PETG does not respond), and paint only after abrasion plus adhesion primer.
Surface treatments FabDigit runs on polymer parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Coating
Coloring
Metallization / Functional
Equivalent designations
Standards and trade names that resolve to PETG-CF in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- CF PETGPETG CF
- Also called
- Carbon Fiber PETG
How much does PETG-CF cost?
PETG-CF is a standard-cost polymer ($$), cheaper than about 99% 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.
PETG-CF — frequently asked
What is PETG-CF used for?
PETG-CF is typically used for functional brackets, enclosures and tooling. In short: stiff carbon-filled PETG.
What is the yield strength of PETG-CF?
PETG-CF has a typical yield strength of 50 MPa (7.25 ksi) and a tensile strength of 52 MPa (7.54 ksi) — stronger than 52% of polymer grades. Strength varies by condition: see the 5 listed tempers.
Is PETG-CF easy to machine?
Reasonably — machinability is rated good (62/100, better than 60% of polymer grades). Drills, mills and taps easily at high speed with sharp carbide and light feeds; carbon fiber is abrasive and dust should be extracted, and keep tools cool to avoid smearing near Tg.
Can PETG-CF be welded?
With care — weldability is rated fair (45/100). Hot-plate, hot-gas and ultrasonic welding work on the matrix but fiber at the joint cuts strength; solvent/adhesive bonding needs sanding plus cyanoacrylate or epoxy since PETG resists most solvents.
What surface finishes work on PETG-CF?
Comes out matte black and hides layer lines well; sand or bead-blast for uniformity, avoid solvent vapor smoothing (PETG does not respond), and paint only after abrasion plus adhesion primer.
Can PETG-CF be formed, bent or molded?
Print at 240–260 °C nozzle / 70–85 °C bed with a hardened steel or ruby nozzle ≥0.4 mm, dry the filament 4–6 h at 65 °C, and use slow first layers and generous cooling; injection molding requires drying and low shear to preserve fiber length.
What is the maximum service temperature of PETG-CF?
PETG-CF is rated for continuous use to about 68°C (154 °F), and briefly to 85°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between PETG-CF CF20 and PETG-CF R?
CF20 is the default condition — default commercial PETG-CF filament: best balance of stiffness, matte finish and printability on a hardened 0.4–0.6 mm nozzle. R: cost- and footprint-driven choice for non-critical prints; expect wider batch-to-batch spread in strength, colour and diameter. Yield strength is 50 MPa in CF20 versus 43 MPa in R.
How much does PETG-CF cost?
PETG-CF is a standard-cost polymer ($$), cheaper than about 99% 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.
Can FabDigit make parts in PETG-CF?
Yes — PETG-CF is available for 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- PETG-CF filament technical data sheet — Bambu Lab (2024)
- CarbonX PETG+CF carbon fiber PETG filament TDS — 3DXTech (2023)
- PETG-CF / PolyLite PETG technical data — Polymaker (2024)
- Eastar / Eastman copolyester (PETG) product data — Eastman Chemical (2022)
- Copolyester and short-fiber compound property records — CAMPUS Plastics (2024)
- ASTM D638 / D790 / D256 test methods for plastics — 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.