Carbon Fiber
also CFRP, CFF
Carbon Fiber (CFRP) is a laminated composite of continuous or chopped carbon fiber in a resin matrix — epoxy as standard, PEEK or BMI where higher temperature is needed — supplied as UD tape, 2x2 woven plate, chopped-fiber compound and printed stock.
Values for the Epoxy Matrix condition
Carbon Fiber grades and fills
Carbon Fiber is supplied in 7 conditions, soft to hard. Epoxy Matrix is the default FabDigit quotes; the values on this page are for it.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
compression-molded chopped prepreg or SMC | Pick for complex net-shape parts and thick sections where quasi-isotropic mid-level properties are enough. | 250 | 0.9 | ||
Woven 2×2 Twill / Plain | Pick for panels, plates and cosmetic parts needing equal 0/90 properties and drapeable layup. | 620 | 1.2 | ||
Epoxy MatrixDefault woven-fabric epoxy prepreg laminate (autoclave/press cured) | Default general-purpose CFRP: 3K twill/plain woven fabric in 120–180 °C cure epoxy, balanced 0/90 properties, panels and plates. | 650 | 1.2 | ||
high-modulus PAN or pitch fiber epoxy laminate (UD, 0°) | Pick when stiffness and dimensional stability dominate (optical benches, satellite structures); strength and toughness are sacrificed. | 1,300 | 0.4 | ||
high-temperature laminate | Pick when continuous service is 180–230 °C (engine nacelles, hot structure, high-speed airframe) and low outgassing is required. | 1,900 | 1.4 | ||
CF/PEEK thermoplastic composite (APC-2 type, UD) | Pick for 250 °C service, hot-wet/chemical exposure, weldable and reformable thermoplastic structure. | 2,070 | 1.4 | ||
Unidirectional prepreg laminate, 0° fiber direction | Pick for maximum stiffness/strength along one axis: spars, tubes, pultruded rods, stiffening caps. | 2,100 | 1.5 |
What is Carbon Fiber?
Carbon Fiber (CFRP) is a laminated composite of continuous or chopped carbon fiber in a resin matrix — epoxy as standard, PEEK or BMI where higher temperature is needed — supplied as UD tape, 2x2 woven plate, chopped-fiber compound and printed stock. At 1.55 g/cm³ with 650 MPa tensile strength, 70 GPa modulus and 1.2% elongation, specific strength and stiffness exceed aluminium alloys and thermal expansion is close to zero. Properties are strongly anisotropic, so design values must be given per layup. Standard epoxy limits service to about 120 °C (Tg 125 °C); interlaminar and compressive strength are low, UV and impact resistance are poor, and contact with aluminium causes galvanic corrosion. Carbon Fiber has a density of 1.55 g/cm³ (0.056 lb/in³), lighter than 56% of composite grades. Its glass-transition temperature is 125°C (257 °F). Carbon Fiber has a tensile strength of 650 MPa (94.3 ksi), stronger than 71% of composite grades. Elongation at break is 1.2% and the elastic modulus is 70 GPa (10.2 Msi).
What is Carbon Fiber used for?
- Aerospace structural panels
- Bicycle frames
- UAV airframes and booms
- Robot arms and end effectors
- Motorsport bodywork and aerodynamic parts
- Machine tool gantries and idler rollers
- Satellite optical benches
- Lightweight drive shafts and tubing
Advantages
- Low, predictable mold shrinkage — 0.1%, better than 100% of composite grades
- Polishes to a fine finish — 60/100, better than 90% of composite grades
- Tough — resists crack growth — 30 MPa·√m (27.3 ksi·√in), better than 85% of composite grades
- Low moisture uptake — 0.1%, better than 85% of composite grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 78% of composite grades
Carbon Fiber properties
Typical room-temperature values for Carbon Fiber-Epoxy Matrix; bars are the position among composite grades.
Physical4
Carbon Fiber has a density of 1.55 g/cm³ (0.056 lb/in³), lighter than 56% of composite grades. Its glass-transition temperature is 125°C (257 °F).
Mechanical11
Carbon Fiber has a tensile strength of 650 MPa (94.3 ksi), stronger than 71% of composite grades. Elongation at break is 1.2% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal9
Carbon Fiber is rated for continuous service to 120°C (248 °F). It conducts heat at 5 W/m·K (2.89 BTU/hr·ft·°F), better than 64% of composite grades. Thermal expansion is 2 µm/m·K (1.11 µin/in·°F).
Electrical3
Carbon Fiber has an electrical resistivity of 0.0015 Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of composite grades. UV resistance is fair.
Sustainability4
Producing a kilogram of Carbon Fiber takes about 350 MJ of energy and emits 24 kg of CO₂ — more than 75% of composite grades. Typical recycled content is 0%.
Manufacturability3
Carbon Fiber's machinability is fair (35/100, better than 50% of composite grades).
Common Calculations4
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 composite family
Yield strength against density for every composite grade FabDigit runs. Carbon Fiber is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Carbon Fiber
Is Carbon Fiber easy to machine?
Use PCD/diamond-coated or diamond-abrasive tooling, high speed and low feed with backing support to avoid delamination and fiber pull-out; vacuum extraction is mandatory (conductive, respirable dust) and coolant/tool wear is the cost driver.
Can Carbon Fiber be welded?
Thermoset CFRP cannot be welded — join by adhesive bonding (peel-ply/abraded surfaces) or bolted joints with generous bearing area; thermoplastic-matrix (PEEK/PA) variants can be induction, resistance or ultrasonically welded.
Can Carbon Fiber be formed, bent or molded?
Formed by prepreg hand layup/AFP with autoclave or press cure (120–180 °C), RTM/infusion of dry fabric, filament winding, pultrusion, or chopped-prepreg compression molding; thermoplastic tapes are stamp-formed above Tm.
Manufacturability
The process limits FabDigit's quote engine applies to Carbon Fiber. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Fair35 / 100 |
|---|---|
| Cutting speed (rough / finish) | — / — |
| Minimum wall | — |
| Minimum internal radius | — |
| Drill depth limit | |
| Best surface (machined / polished) | Ra — / — |
| Hardenable after machining | — |
Sheet metal
| Formability | Not Recommend5 / 100 |
|---|---|
| Weldability | Not Recommend5 / 100 |
Carbon Fiber 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 (PAN-based, T300/T700 classwt %; ≈50–60 vol % for autoclave prepreg laminates | 50 – 70 | 60 |
| sizing / interlayer toughenerfiber sizing plus thermoplastic toughening particles in aerospace prepregs | 0 – 2 | 1 |
| epoxy resin matrixDGEBA/amine or 180 °C-cure toughened epoxy; substituted by PEEK, BMI, cyanate ester or PA in other variants | ≥ 30 (balance) |
What surface finishes work on Carbon Fiber?
Cannot be anodized or plated conventionally; finish by resin/gel surfacing film, filler-primer and 2K clear or paint with UV blocker, and always isolate from aluminium/steel with glass-fiber ply or sealant to prevent galvanic corrosion.
Surface treatments FabDigit runs on composite 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).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Carbon Fiber in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- CFRPCFFGraphite Composite
- Also called
- Continuous Carbon Fiber
How much does Carbon Fiber cost?
Carbon Fiber is a premium-cost composite ($$$), pricier than about 58% 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.
Carbon Fiber — frequently asked
What is Carbon Fiber used for?
Carbon Fiber is typically used for aerospace structural panels, bicycle frames, UAV airframes and booms, robot arms and end effectors, motorsport bodywork and aerodynamic parts and machine tool gantries and idler rollers. In short: lightweight aerospace laminate.
What is the tensile strength of Carbon Fiber?
Carbon Fiber has a typical tensile strength of 650 MPa (94.3 ksi) — stronger than 71% of composite grades. Strength varies by condition: see the 7 listed tempers.
Is Carbon Fiber easy to machine?
Not especially — machinability is rated fair (35/100, better than 50% of composite grades). Use PCD/diamond-coated or diamond-abrasive tooling, high speed and low feed with backing support to avoid delamination and fiber pull-out; vacuum extraction is mandatory (conductive, respirable dust) and coolant/tool wear is the cost driver.
Can Carbon Fiber be welded?
Thermoset CFRP cannot be welded — join by adhesive bonding (peel-ply/abraded surfaces) or bolted joints with generous bearing area; thermoplastic-matrix (PEEK/PA) variants can be induction, resistance or ultrasonically welded.
What surface finishes work on Carbon Fiber?
Cannot be anodized or plated conventionally; finish by resin/gel surfacing film, filler-primer and 2K clear or paint with UV blocker, and always isolate from aluminium/steel with glass-fiber ply or sealant to prevent galvanic corrosion.
Can Carbon Fiber be formed, bent or molded?
Formed by prepreg hand layup/AFP with autoclave or press cure (120–180 °C), RTM/infusion of dry fabric, filament winding, pultrusion, or chopped-prepreg compression molding; thermoplastic tapes are stamp-formed above Tm.
What is the maximum service temperature of Carbon Fiber?
Carbon Fiber is rated for continuous use to about 120°C (248 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Carbon Fiber cost?
Carbon Fiber is a premium-cost composite ($$$), pricier than about 58% 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 Carbon Fiber?
Yes — Carbon Fiber is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- CMH-17 Composite Materials Handbook, Vol. 2 (Polymer Matrix Composites — Material Properties) — SAE International / CMH-17 (2012)
- ASM Handbook Vol. 21: Composites — ASM International (2001)
- T300 / T700S / M55J carbon fiber and prepreg data sheets — Toray Composite Materials (2023)
- HexPly 8552 / 913 prepreg and HexTow fiber data sheets — Hexcel (2023)
- APC-2 / AS4-PEEK thermoplastic tape data sheet — Solvay (Cytec) (2022)
- Continuous Fiber Reinforcement (CFF/CFR) material properties — Markforged (2023)
- ASTM D3039 / D6641 / D7264 / D2344 composite test methods — ASTM International (2021)
- CES / Ashby material property and eco-property data for CFRP — Ansys Granta (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.