Markforged Onyx Filament Review & Alternatives [2024]

Madeline Hogan

Markforged Onyx is a popular composite material used for various 3D printing applications. However, it’s also one of the most expensive 3D printing materials on the market. Is it worth the investment?

We dive into the specifics of Markforged Onyx in this review and share a few alternatives that may be more cost-effective or offer a more favorable mix of material properties for your use case.

What is Markforged’s Onyx carbon fiber?

Markforged Onyx is a proprietary material developed by Markforged, a US-based 3D printing company. It’s a microcarbon fiber-filled nylon that’s 1.4x stronger and stiffer compared to ABS. Onyx is suitable for a variety of demand applications because it offers an excellent surface finish, chemical resistance, and heat tolerance.

Markforged Onyx Filament Review

Let’s dive into the specifics of Markforged Onyx and its mechanical properties.

Onyx Variants

Onyx Variants

Markforged offers three Onyx variants:

  • Onyx: A micro carbon fiber-filled nylon that offers excellent strength, stiffness, surface finish, chemical resistance, and heat tolerance.
  • Onyx FR: A flame retardant version of Onyx. It’s UL94 V-0 certified and used for applications that require fire resistance.
  • Onyx ESD: A static dissipative variant of Onyx. It’s designed for environments that require ESD protection while retaining standard Onyx’s mechanical strength and surface finish.

Onyx Filament Strength

Onyx is 1.4x stronger and stiffer than ABS. You can also reinforce it with continuous fibers like carbon fiber to achieve even greater strength. Here are some material properties to give you an overview of Onyx’s strength:

  • Tensile strength: As determined through ASTM D638 testing, Onyx achieves a tensile stress at yield of 40 MPa and tensile stress at break of 37 MPa.
  • Flexural strength: Onyx can resist deformation under load with a flexural strength of 71 MPa, as tested via ASTM D790.
  • Tensile modulus: The tensile modulus of 2.4 GPa shows Onyx’s high stiffness when subjected to tensile forces.
  • Izod impact (Notched): The impact strength of 330 J/m indicates Onyx is resilient to sudden forces and shocks.
  • Elongation at break: Onyx has an elongation at break of 25%, which means it can stretch up to a quarter of its original length before failing.

Markforged Onyx Melting Temperature

Onyx is a thermoplastic. It doesn’t have a traditional melting point but has a Heat Deflection Temperature (HDT)—the temperature at which Onyx maintains its shape under a specified load—of 145°C (measured at 0.45 Mpa, 66 psi) or roughly 293°F, according to ASTM D648 testing. This makes Onyx suitable for applications where parts may be subjected to high temperatures during use.

​​Markforged Onyx Print Temperature

The recommended print temperature range for Onyx is between 220°C and 240°C. Using this extrusion temperature is important to effectively melt the micro carbon fiber-filled nylon, ensure proper material flow, promote smooth layer adhesion, and reduce the risk of warping and delamination.

Other Onyx Filament Material Properties

Here are some other properties of Onyx:

  • Surface finish: Onyx offers a suitable surface finish.
  • Chemical resistance: Onyx can withstand exposure to a broad range of chemicals.
  • Flame retardancy: Onyx FR is UL94 V-0 certified, making it a good option for applications where fire safety is a priority.
  • Static dissipation: Onyx ESD is a static dissipative variant of Onyx. It meets ESD safety requirements and offers protection against static discharge.
  • Density: Onyx has a density of 1.2 g/cm³. It’s lightweight and offers robust characteristics, making it easier to handle and suitable for a wide range of applications.
  • Versatility: You can print Onyx alone or reinforce it with continuous fibers such as Carbon Fiber, Kevlar, or Fiberglass. This allows you to tailor the part’s mechanical properties and expand its application scope across various industries.

Onyx Applications

Onyx is used across various industries. Here are some key applications of Onyx:

  • Functional prototypes: Onyx offers a good surface finish and mechanical properties, you can use it for functional prototypes that require durability and aesthetic appeal.
  • Tooling: Onyx offers good strength and can produce complex geometries. This allows for the creation of custom jigs, fixtures, and other tooling solutions.
  • Customized equipment: You can tailor Onyx to specific load requirements in high-performance applications through reinforcement with continuous fibers like Carbon Fiber.
  • End-use parts: Onyx can replace metal parts while maintaining performance and reducing weight. You can use it for end-use parts in aerospace, automotive, and industrial applications.
  • Electrical enclosures: Onyx ESD is designed for static dissipative applications, which means it’s suitable for enclosures in sensitive electronic components.
  • Flame-retardant applications: Onyx FR is certified to UL94 V-0 which means it can be used in environments with flammable materials.

Markforged Onyx Pricing

Here’s the pricing for all Onyx variants:

  • Onyx: $190/800cc
  • Onyx FR: $230/800cc
  • Onyx ESD: $230/800cc

Pros

  • Strength and durability: Onyx is 1.4x stronger and stiffer than ABS.
  • Good surface finish: Onyx produces high-quality prints with great aesthetic appeal.
  • Chemical resistance: Capable of withstanding exposure to various chemicals, making it usable in diverse environments.
  • Versatile reinforcement: Performance can be improved by reinforcement with continuous fibers.

Cons

  • Expensive: Onyx is more expensive than standard thermoplastics.
  • Printer compatibility: Onyx is designed to work specifically with Markforged printers designed for composite materials. This limits options for users with other printers.

Best Onyx 3D Printer Material Alternatives

There are better 3D printer materials out there than Onyx. Here are two key alternatives to consider before you settle on a material:

1. Nexa3D’s Xyon

Nexa3D’s Xyon

Nexa3D’s Xyon is a high-performance filament and the best alternative to Markforged’s Onyx for a wide range of 3D printing applications.

Xyon works perfectly with your existing Markforged printers, so you don’t need a new 3D printer to use it. It offers superior tensile strength, flexibility, and thermal stability and its carbon-fiber-reinforced nylon composite ensures that all parts you produce are durable as well as lightweight.

Whether you’re looking for a material for prototyping or need to produce functional parts, Xyon can help you achieve the desired precision and strength. It does this while keeping costs to a minimum—delivering both performance and value.

Material properties:

  • Tensile Strength at Yield: 40.7 MPa
  • Elongation at Break: 15.2%
  • Young’s Modulus: 1.6 GPa
  • Flexural Strength: 58 MPa
  • Flexural Modulus: 1.6 GPa
  • Heat Deflection Temperature (HDT): 135 °C
  • Density: 1.10 g/cm³

Onyx vs Xyon

Xyon offers stronger tensile strength at yield than Onyx of 40.7 MPa. While Onyx has a higher elongation at break, indicating it offers slightly better flexibility, Xyon’s impact strength and heat deflection temperature (135 °C) are optimized for performance in demanding environments. You can also look at Xyon as a more cost-effective option that doesn’t compromise print quality and delivers top-notch strength, stiffness, and thermal resistance.

If you’re looking for a combination of high strength, flexibility, and impact resistance, place your first order for Xyon.

2. 3DXTech Obsidian™-GF Glass Fiber Reinforced PA6

3DXTech Obsidian

3DXTech’s Obsidian GF+PA6 filament is a cost-effective alternative to Onyx for 3D printing. The filament is compatible with Markforged printers as well as other PA6+GF-compatible devices.

It’s a glass fiber-reinforced nylon filament that offers good strength, stiffness, and dimensional stability—it has a tensile strength of up to 60 MPa and a flexural strength of 90 MPa. The material is reinforced with glass fiber, which improves its impact resistance and makes it durable for functional applications.

Obsidian GF+PA6 is engineered to operate between 80–120°C and has a melting temperature of 220°C. The high melting point ensures durability and resistance to deformation under heat, making it suitable for functional parts, while the lower temperature range indicates good printability and reduces warping during printing.

Material properties:

  • Tensile Strength at Yield: 44 MPa
  • Elongation at Break: 11%
  • Young’s Modulus: 3.5 GPa
  • Flexural Strength: 75 MPa
  • Flexural Modulus: 3.8 GPa
  • Heat Deflection Temperature (HDT): 147°C
  • Density: 1.2 g/cm³

Onyx vs Obsidian vs Xyon

Onyx, Obsidian, and Xyon offer various distinct capabilities, but Xyon is a front-runner with its combination of affordability and balanced performance.

Xyon offers excellent tensile strength and flexibility, as indicated by its high tensile strength and low tensile modulus, making it the perfect choice for applications where slight pliability is beneficial.

Xyon is also the lightest alternative and great for weight-sensitive applications where you can’t compromise too much on strength.

Learn more about Onyx

Now that we’ve covered the basics, let’s address some common questions you may have about Onyx.

What is the alternative filament to Onyx?

Xyon is the best alternative filament to Onyx because it offers better tensile strength and a smoother surface finish for a lower cost.

Is Onyx stronger than PLA?

Yes, Onyx is stronger than PLA because it’s a carbon fiber-filled nylon composite. It offers higher tensile strength, stiffness, and thermal resistance. However, if you’re looking for enhanced flexibility and impact resistance, consider Xyon, which is also stronger than PLA thanks to better impact resistance and flexibility and a higher heat deflection temperature.

Is Markforged Onyx PA6 or PA12?

Markforged Onyx is PA6 (nylon) reinforced with micro-carbon fibers.

What is the strongest printable plastic?

PEEK (Polyether Ether Ketone) is the strongest printable plastic with a tensile strength that exceeds 90 MPa.

Choose the best carbon fiber for 3D printing

Onyx is strong, offers high-quality surface finish, and can withstand high temperatures without deflecting. However, it offers limited flexibility and is expensive compared to its alternatives.

If you’re looking for a versatile alternative to Onyx that can be used for a wide range of applications, from prototyping to end-use parts, and offers a high-quality surface finish, Xyon is the best, most cost-effective option.

Xyon offers an excellent balance between strength, flexibility, and impact resistance. It also offers superior elongation at break, making it suitable for applications that require flexibility.

The best part? It offers seamless compatibility with Markforged setups, so there’s no need to modify your printing processes.

Contact us today to learn more about Xyon or place your first order for Xyon.