Carbon Fiber · grade
Carbon Fiber HM Pitch
Properties of the HM Pitch condition, compared with the other Carbon Fiber grades.
Pick when stiffness and dimensional stability dominate (optical benches, satellite structures); strength and toughness are sacrificed.
What is Carbon Fiber HM Pitch?
Carbon Fiber HM Pitch is Carbon Fiber in the HM Pitch grade — pick when stiffness and dimensional stability dominate (optical benches, satellite structures); strength and toughness are sacrificed. Carbon Fiber HM Pitch has a tensile strength of 1,300 MPa (189 ksi), stronger than 71% of composite grades. Elongation at break is 0.4% and the elastic modulus is 280 GPa (40.6 Msi). Carbon Fiber HM Pitch has a density of 1.68 g/cm³ (0.0607 lb/in³), lighter than 53% of composite grades. Its glass-transition temperature is 125°C (257 °F). Epoxy Matrix is the default condition FabDigit quotes; HM Pitch is available on request or by drawing note.
Advantages
- Low, predictable mold shrinkage — 0.1%, better than 100% of composite grades
- Polishes to a fine finish — 60/100, better than 89% of composite grades
- Stiff — 280 GPa (40.6 Msi), better than 88% of composite grades
- Conducts heat well — 90 W/m·K (52 BTU/hr·ft·°F), better than 87% of composite grades
- Tough — resists crack growth — 30 MPa·√m (27.3 ksi·√in), better than 85% of composite grades
Limitations
- Limited ductility — 0.4%, worse than 91% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 79% of composite grades
Carbon Fiber HM Pitch properties
Typical room-temperature values for Carbon Fiber HM Pitch — 10 properties are specific to this condition; the rest are grade-level values shared by every Carbon Fiber grade. Each bar shows where the value sits among the composite grades in FabDigit's library — further right is higher.
Physical4
Carbon Fiber HM Pitch has a density of 1.68 g/cm³ (0.0607 lb/in³), lighter than 53% of composite grades. Its glass-transition temperature is 125°C (257 °F).
Mechanical11
Carbon Fiber HM Pitch has a tensile strength of 1,300 MPa (189 ksi), stronger than 71% of composite grades. Elongation at break is 0.4% and the elastic modulus is 280 GPa (40.6 Msi).
Thermal9
Carbon Fiber HM Pitch is rated for continuous service to 120°C (248 °F). It conducts heat at 90 W/m·K (52 BTU/hr·ft·°F), better than 87% of composite grades. Thermal expansion is -1 µm/m·K (-0.556 µin/in·°F).
Electrical3
Carbon Fiber HM Pitch has an electrical resistivity of 3×10⁻⁴ 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 HM Pitch takes about 350 MJ of energy and emits 24 kg of CO₂ — more than 74% of composite grades. Typical recycled content is 0%.
Manufacturability3
Carbon Fiber HM Pitch's machinability is fair (35/100, better than 50% of composite grades).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Carbon Fiber grades and fills
Carbon Fiber is also supplied in 7 other conditions. The full side-by-side table is on the Carbon Fiber overview.
- Epoxy MatrixDefaultDefault general-purpose CFRP: 3K twill/plain woven fabric in 120–180 °C cure epoxy, balanced 0/90 properties, panels and plates.650 MPa tensile
- UDPick for maximum stiffness/strength along one axis: spars, tubes, pultruded rods, stiffening caps.2,100 MPa tensile
- PEEK MatrixPick for 250 °C service, hot-wet/chemical exposure, weldable and reformable thermoplastic structure.2,070 MPa tensile
- BMI MatrixPick when continuous service is 180–230 °C (engine nacelles, hot structure, high-speed airframe) and low outgassing is required.1,900 MPa tensile
- HM PitchPick when stiffness and dimensional stability dominate (optical benches, satellite structures); strength and toughness are sacrificed.1,300 MPa tensile
- As PrintedPick for fast, tool-free stiff brackets and jigs: continuous carbon fiber laid into a nylon/Onyx matrix, anisotropic and layer-limited.800 MPa tensile
- Woven 2x2Pick for panels, plates and cosmetic parts needing equal 0/90 properties and drapeable layup.620 MPa tensile
- Chopped CFPick for complex net-shape parts and thick sections where quasi-isotropic mid-level properties are enough.250 MPa tensile
Working with Carbon Fiber HM Pitch
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.
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.
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) | — |
Carbon Fiber HM Pitch — frequently asked
What is Carbon Fiber HM Pitch used for?
Carbon Fiber HM Pitch 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 HM Pitch?
Carbon Fiber HM Pitch has a typical tensile strength of 1,300 MPa (189 ksi) — stronger than 71% of composite grades. Strength varies by condition: see the 8 listed tempers.
Is Carbon Fiber HM Pitch 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 HM Pitch 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 HM Pitch?
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 HM Pitch 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 HM Pitch?
Carbon Fiber HM Pitch 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.
Can FabDigit make parts in Carbon Fiber HM Pitch?
Yes — Carbon Fiber HM Pitch 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.