Markforged FX20

$100,000 - $150,000 Updated 2026-03-16

Key Specifications

build volume

525 x 400 x 400 mm (20.7 x 15.7 x 15.7 in)

technology

Continuous Fiber Reinforcement (CFR) + FFF

base materials

Onyx (chopped carbon fiber + nylon), ULTEM 9085

reinforcement fibers

Carbon Fiber, Fiberglass, Kevlar, HSHT Fiberglass

layer thickness

100 µm (base), 125 µm (fiber)

tensile strength cf onyx

700+ MPa (fiber direction)

Overview

The Markforged FX20 is the company's industrial-grade continuous fiber reinforcement (CFR) 3D printer capable of printing with Onyx (chopped carbon fiber + nylon) and continuous fibers including carbon fiber, fiberglass, Kevlar, and HSHT fiberglass — and most notably, aerospace-grade ULTEM 9085 thermoplastic. While the FX20 is a polymer-composite printer rather than a pure metal AM system, it occupies a critical position in the metal-adjacent additive manufacturing landscape: it produces structural composite parts with metal-comparable strength-to-weight ratios and is qualified for aerospace tooling, jigs, fixtures, and flight-adjacent components where aluminum would traditionally be machined.

The FX20 was specifically engineered to address the ULTEM 9085 application space that was previously monopolized by high-temperature FDM systems like the Stratasys Fortus 450mc. ULTEM 9085 is a FAA-recognized material for aircraft interior components and ground support tooling, and Markforged's ability to print it with continuous fiber reinforcement delivers mechanical properties that exceed standard ULTEM FDM parts. The build volume is 525 x 400 x 400 mm — significantly larger than any other Markforged platform — accommodating full-scale aerospace tooling panels, large jigs, and production fixture components that exceed the capacity of competing continuous fiber printers.

The FX20 uses a dual-head system — one head for the base material (Onyx or ULTEM) and one for continuous fiber laydown. The Eiger slicer handles fiber routing, allowing engineers to orient reinforcement in principal stress directions for maximum structural efficiency. Achieved tensile strength in the fiber direction exceeds 700 MPa for carbon fiber Onyx parts — comparable to 6061-T6 aluminum — while maintaining the weight advantage of composite construction and the geometric freedom of additive manufacturing.

The FX20 is positioned between $100,000 and $150,000 and targets aerospace prime contractors, defense integrators, and advanced manufacturing operations that use additive composite tooling as a productivity multiplier. It is not a metal printer in the strict sense, but for applications in metal-adjacent tooling, aerospace fixtures, and structural composite components, the FX20 competes directly with metal AM systems on mechanical performance while offering faster print times and dramatically lower material costs.

Full Specifications

Parameter	Value
Build Volume	525 x 400 x 400 mm (20.7 x 15.7 x 15.7 in)
Technology	Continuous Fiber Reinforcement (CFR) + FFF
Base Materials	Onyx (chopped carbon fiber + nylon), ULTEM 9085
Reinforcement Fibers	Carbon Fiber, Fiberglass, Kevlar, HSHT Fiberglass
Layer Thickness	100 µm (base), 125 µm (fiber)
Tensile Strength Cf Onyx	700+ MPa (fiber direction)
Print Heads	Dual — base material + continuous fiber
Heated Chamber	Yes — required for ULTEM 9085 processing
Software	Eiger (cloud-based) + Digital Forge platform
Connectivity	Cloud-connected, fleet management capable
Machine Dimensions	1,370 x 960 x 1,690 mm
Power Requirements	200-240V, single phase

Specifications sourced from markforged.com — verified 2026-03-28

Strengths & Limitations

Strengths

ULTEM 9085 capability enables FAA-recognized aerospace interior and tooling applications that are unavailable on standard continuous fiber printers
Largest build volume in the Markforged portfolio (525x400x400mm) accommodates full-scale aerospace tooling panels, large fixtures, and production jigs
Carbon fiber Onyx tensile strength exceeds 700 MPa — comparable to 6061-T6 aluminum — at a fraction of the material cost and without post-processing machining for most features
Markforged Digital Forge integration provides fleet management and part traceability for aerospace programs requiring revision control and production records

Limitations

Polymer-composite output is not a substitute for metal in applications requiring conductivity, thermal resistance above ~170°C (ULTEM limit), or high fatigue cycles
Cloud-dependent Eiger software requires internet connectivity — air-gapped aerospace and defense facilities require Private Cloud deployment
Higher material cost for ULTEM 9085 compared to Onyx, and continuous fiber adds per-part material cost that must be factored into ROI vs. machined aluminum tooling

Best For

Aerospace prime contractors and MRO facilities producing ULTEM 9085 tooling, jigs, and interior components with FAA-recognized material compliance Defense manufacturers building large composite structural prototypes and ground support equipment fixtures that replace machined aluminum at lower cost and lead time Advanced manufacturing operations using continuous carbon fiber Onyx parts as functional replacements for aluminum tooling fixtures in assembly and inspection processes Organizations running composite parts programs that need the largest build volume in the Markforged portfolio combined with continuous fiber reinforcement

Frequently Asked Questions

01 Is the Markforged FX20 a metal printer?

No — the FX20 is a continuous fiber reinforcement composite printer, not a metal AM system. It prints Onyx and ULTEM 9085 thermoplastic reinforced with continuous carbon fiber, fiberglass, or Kevlar. However, it occupies the metal-adjacent space: carbon fiber Onyx parts achieve tensile strength comparable to 6061-T6 aluminum, making it a direct competitor to metal AM for tooling, fixtures, and structural components where the temperature and conductivity properties of metal are not required.

02 What makes ULTEM 9085 significant for aerospace?

ULTEM 9085 (PEI) is recognized by the FAA for aircraft interior components under FAR 25.853 flame, smoke, and toxicity (FST) requirements. It is the same base material used in Stratasys Fortus FDM aerospace-grade parts. The FX20 adds continuous fiber reinforcement to ULTEM, enabling higher stiffness and strength than standard ULTEM FDM parts — making it suitable for more demanding tooling and structural applications in aerospace environments.

03 How does the FX20 compare to Stratasys Fortus 450mc for aerospace tooling?

Both print ULTEM 9085 for aerospace applications, but the FX20 adds continuous fiber reinforcement that dramatically increases stiffness and strength in critical directions. The Fortus 450mc prints unreinforced ULTEM using Stratasys's larger material library. The FX20's build volume (525x400x400mm) is comparable. The key differentiator is whether continuous fiber reinforcement in ULTEM provides sufficient strength gain for a specific tooling application to justify the FX20 over the established Fortus platform.

04 What is the tensile strength of Markforged FX20 parts?

Carbon fiber reinforced Onyx parts printed on the FX20 achieve tensile strength exceeding 700 MPa in the fiber direction — comparable to 6061-T6 aluminum (276 MPa yield, 310 MPa UTS). ULTEM 9085 parts with continuous carbon fiber reinforcement achieve similar improvements over unreinforced ULTEM. Actual strength depends on fiber volume fraction and orientation, which the Eiger slicer optimizes based on part geometry and load case inputs.

05 What is the Markforged FX20 price?

The FX20 is typically priced at $100,000 to $150,000 depending on configuration and options. Eiger software subscriptions are required for operation. Material costs include Onyx or ULTEM spools plus continuous fiber spools, priced per spool. Compared to machined aluminum tooling or LPBF metal AM systems, the FX20 typically offers lower cost-per-part for fixture and tooling applications where metal-equivalent structural performance is achievable with composites.