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Onyx As Printed

Print state · default condition

also Markforged Onyx, Onyx CF

Default choice for jigs, fixtures and covers where stiffness and surface finish matter more than ultimate strength.

3D printingHigh cost $$$$

Values for the As Printed condition

Other Onyx grades and fills

Onyx is listed in 8 conditions; see the grade overview at Onyx.

Compare all 8 grades and fillsHide
Grade · open for datasheetBest forYield MPaTensile MPaElong. %Hardness
As PrintedDefaultThis page
standard Onyx, no continuous fiber
Default choice for jigs, fixtures and covers where stiffness and surface finish matter more than ultimate strength.37402580 Shore D
Onyx ESD
Choose for electronics handling fixtures, wafer/PCB tooling and any part that must bleed off static charge.42421280 Shore D
Onyx FR
Pick when the printed part must meet UL 94 V-0 flammability, e.g. electrical enclosures and rail/industrial interiors.4850882 Shore D
Onyx FR-A
Use for aircraft interior brackets and tooling where FST/FAR 25.853 vertical burn compliance and material traceability are required.4850882 Shore D
Onyx + Continuous Fiberglass
Lowest-cost continuous reinforcement: strong but much less stiff than carbon, and electrically non-conductive.5903.884 Shore D
high strength / high temperature fiberglass
Choose when reinforced parts see elevated temperature or need higher impact toughness than standard fiberglass.6004.284 Shore D
Onyx + Continuous Kevlar
Pick for impact-absorbing, abrasion-prone or shock-loaded parts where ductile failure is preferred over brittle carbon fracture.6102.782 Shore D
Onyx + Continuous Carbon Fiber
Use when a printed part must replace machined aluminium in stiffness/strength; values apply along the continuous fiber direction only.8001.585 Shore D

What is Onyx As Printed?

Onyx As Printed is Onyx in the As Printed condition — default choice for jigs, fixtures and covers where stiffness and surface finish matter more than ultimate strength. Onyx As Printed has a yield strength of 37 MPa (5.37 ksi) and a tensile strength of 40 MPa (5.8 ksi) — weaker than 84% of composite grades. Elongation at break is 25% and the elastic modulus is 2.4 GPa (0.348 Msi). Onyx As Printed has a density of 1.2 g/cm³ (0.0434 lb/in³), lighter than 79% of composite grades. Its glass-transition temperature is 60°C (140 °F).

Advantages

  • Ductile — tolerates forming and impact — 25%, better than 98% of composite grades
  • Lightweight — 1.2 g/cm³ (0.0434 lb/in³), better than 79% of composite grades

Limitations

  • Limited service temperature — 110°C (230 °F), worse than 87% of composite grades
  • Low strength — 37 MPa (5.37 ksi), worse than 84% of composite grades
  • Low stiffness — 2.4 GPa (0.348 Msi), worse than 83% of composite grades
  • Low fracture toughness — 3.5 MPa·√m (3.19 ksi·√in), worse than 77% of composite grades

Onyx As Printed properties

Typical room-temperature values for Onyx As Printed; 21 are specific to this condition. Other listed values are Onyx reference data and may not represent this condition. Bars are the position among composite grades.

Physical5

Onyx As Printed has a density of 1.2 g/cm³ (0.0434 lb/in³), lighter than 79% of composite grades. Its glass-transition temperature is 60°C (140 °F).

Density1.2 g/cm³0.04 lb/in³
Melting Temperature (Tm)200°C392 °F
Glass Transition (Tg)60°C140 °F
Water Absorption (24 h)0.7%
Water Absorption (Saturation)4%

Mechanical12

Onyx As Printed has a yield strength of 37 MPa (5.37 ksi) and a tensile strength of 40 MPa (5.8 ksi) — weaker than 84% of composite grades. Elongation at break is 25% and the elastic modulus is 2.4 GPa (0.348 Msi).

Elastic (Young's) Modulus2.4 GPa0.35 Msi
Tensile Strength (Ultimate)40 MPa5.8 ksi
Yield Strength (0.2% offset)37 MPa5.4 ksi
Elongation at Break25%
Compressive Strength55 MPa8 ksi
Flexural Strength71 MPa10.3 ksi
Flexural Modulus3 GPa0.44 Msi
Shear Strength42 MPa6.1 ksi
Fracture Toughness (K_IC)3.5 MPa·√m3.2 ksi·√in
Izod Impact, Notched330 J/m6.2 ft·lbf/in
Hardness, Shore D80 Shore D
Hardness, Rockwell R112 HRR

Thermal8

Onyx As Printed is rated for continuous service to 110°C (230 °F). It conducts heat at 0.35 W/m·K (0.202 BTU/hr·ft·°F), better than 50% of composite grades. Thermal expansion is 45 µm/m·K (25 µin/in·°F).

Thermal Conductivity0.35 W/m·K0.2 BTU/hr·ft·°F
Specific Heat Capacity1,500 J/kg·K0.36 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)45 µm/m·K25 µin/in·°F
Max Service Temperature (continuous)110°C230 °F
Min Service Temperature-40°C-40 °F
Heat Deflection Temp. @ 0.45 MPa145°C293 °F
Heat Deflection Temp. @ 1.8 MPa68°C154 °F
Limiting Oxygen Index24%

Electrical1

Onyx As Printed has an electrical resistivity of 1×10¹⁰ Ω·m.

Electrical Resistivity1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in

Chemical & Environmental3

Corrosion resistance is excellent (85/100), better than 65% of composite grades. UV resistance is fair.

Corrosion ResistanceExcellent85/100
UV / Weathering ResistanceFair45/100
Chemical Resistance SummaryGood against oils, greases, fuels, aliphatic hydrocarbons and most alkalis; attacked by strong mineral acids, phenols, formic acid and chlorinated solvents; absorbs moisture which softens the part and lowers stiffness.

Sustainability3

Producing a kilogram of Onyx As Printed takes about 135 MJ of energy and emits 8 kg of CO₂ — less than 55% of composite grades. Typical recycled content is 0%.

Embodied Energy (primary production)135 MJ/kg58,040 BTU/lb
Embodied Carbon (primary production)8 kg CO₂/kg
Typical Recycled Content0%

Manufacturability4

Onyx As Printed's machinability is good (55/100, better than 71% of composite grades).

MachinabilityGood55/100
PolishabilityPoor30/100
Mold Shrinkage0.4%
Processing Melt Temperature (typ.)270°C518 °F

Common Calculations5

Specific Strength (UTS / density)calculated33 kN·m/kg
Specific Stiffness (E / density)calculated2 MN·m/kg
Modulus of Resiliencecalculated285 kJ/m³
Thermal Diffusivitycalculated0.2 mm²/s
Thermal Shock Resistance Indexcalculated0

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Onyx As Printed

Is Onyx easy to machine?

Drilling/reaming and light milling are fine with sharp carbide tools, but the chopped carbon fiber is abrasive and cutting into sparse infill exposes voids — design in solid regions where you plan to machine.

Can Onyx be welded?

Not weldable in the metal sense; parts are joined with cyanoacrylate/epoxy adhesive, threaded inserts or mechanical fasteners after light surface abrasion.

Can Onyx be formed, bent or molded?

Processed only by FFF extrusion at roughly 260–285 °C on Markforged printers; dry the spool before use, keep walls ≥ 4 layers and orient loads in-plane to avoid weak Z-axis interlayer failure.

What surface finishes work on Onyx?

Prints leave a matte black surface that needs no painting; sanding, filling and adhesion-promoter primer are required if coating, and no anodizing/plating applies.

Onyx 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.

ElementSpec limit (wt %)Nominal
chopped (micro) carbon fiberloading not published by producer; SDS indicates <20 wt%5 – 2012
polyamide (PA6/PA66) matrixsemi-crystalline nylon copolymer base resinbalance

Onyx As Printed — frequently asked

What is Onyx As Printed used for?

Onyx As Printed is typically used for jigs, fixtures and tooling. In short: carbon-filled tough nylon.

What is the yield strength of Onyx As Printed?

Onyx As Printed has a typical yield strength of 37 MPa (5.37 ksi) and a tensile strength of 40 MPa (5.8 ksi) — weaker than 84% of composite grades. Strength varies by condition: see the 8 listed tempers.

Is Onyx As Printed easy to machine?

Reasonably — machinability is rated good (55/100, better than 71% of composite grades). Drilling/reaming and light milling are fine with sharp carbide tools, but the chopped carbon fiber is abrasive and cutting into sparse infill exposes voids — design in solid regions where you plan to machine.

Can Onyx As Printed be welded?

Not weldable in the metal sense; parts are joined with cyanoacrylate/epoxy adhesive, threaded inserts or mechanical fasteners after light surface abrasion.

What surface finishes work on Onyx As Printed?

Prints leave a matte black surface that needs no painting; sanding, filling and adhesion-promoter primer are required if coating, and no anodizing/plating applies.

Can Onyx As Printed be formed, bent or molded?

Processed only by FFF extrusion at roughly 260–285 °C on Markforged printers; dry the spool before use, keep walls ≥ 4 layers and orient loads in-plane to avoid weak Z-axis interlayer failure.

What is the maximum service temperature of Onyx As Printed?

Onyx As Printed is rated for continuous use to about 110°C (230 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between Onyx As Printed and Onyx FR?

As Printed is the default condition — default choice for jigs, fixtures and covers where stiffness and surface finish matter more than ultimate strength. FR: pick when the printed part must meet UL 94 V-0 flammability, e.g. electrical enclosures and rail/industrial interiors. Yield strength is 37 MPa in As Printed versus 48 MPa in FR.

Can FabDigit make parts in Onyx As Printed?

Yes — Onyx As Printed is available for 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. Markforged Composites Material Datasheet (Onyx, Onyx FR, Onyx ESD, CFF fibers) — Markforged (2023)
  2. Onyx Safety Data Sheet / filament technical bulletin — Markforged (2022)
  3. ASTM D638 / D790 / D256 / D648 test methods referenced by the producer — ASTM International (2022)
  4. Engineering property data for carbon-fiber-filled polyamide (matrix baseline values) — ASM International / CAMPUS polymer data (2020)
  5. 3D Markforged Onyx (2026)

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.