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Onyx · print state · default condition

Onyx As Printed

Properties of the As Printed condition, compared with the other Onyx grades.

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

3D printingHigh cost $$$$

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 40 MPa (5.8 ksi) and a tensile strength of 40 MPa (5.8 ksi) — weaker than 100% 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

  • Low strength — 40 MPa (5.8 ksi), worse than 100% of composite grades
  • Limited service temperature — 110°C (230 °F), worse than 88% of composite grades
  • Low stiffness — 2.4 GPa (0.348 Msi), worse than 86% of composite grades

Onyx As Printed properties

Typical room-temperature values for Onyx As Printed — 9 properties are specific to this condition; the rest are grade-level values shared by every Onyx grade. Each bar shows where the value sits among the composite grades in FabDigit's library — further right is higher.

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%

Mechanical9

Onyx As Printed has a yield strength of 40 MPa (5.8 ksi) and a tensile strength of 40 MPa (5.8 ksi) — weaker than 100% 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)40 MPa5.8 ksi
Elongation at Break25%
Flexural Strength71 MPa10.3 ksi
Flexural Modulus3 GPa0.44 Msi
Izod Impact, Notched330 J/m6.2 ft·lbf/in
Hardness, Shore D80 Shore D
Hardness, Rockwell R112 HRR

Thermal7

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

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 56% 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%

Manufacturability3

Onyx As Printed's machinability is good (55/100, better than 72% of composite grades).

MachinabilityGood55/100
PolishabilityPoor30/100
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 Resiliencecalculated333 kJ/m³
Thermal Diffusivitycalculated0.2 mm²/s
Thermal Shock Resistance Indexcalculated0

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other Onyx grades and fills

Onyx is also supplied in 7 other conditions. The full side-by-side table is on the Onyx overview.

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 40 MPa (5.8 ksi) and a tensile strength of 40 MPa (5.8 ksi) — weaker than 100% 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 72% 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.

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 bulletinMarkforged (2022)
  3. ASTM D638 / D790 / D256 / D648 test methods referenced by the producerASTM 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.