New EOS M4 ONYX unlocks 50% higher throughput for metal AM

Among the many announcements at Formnext 2025, EOS’ new hardware launch is certainly one of the most anticipated. The company, a leader in powder-based polymer and metal AM solutions, has today unveiled the EOS M4 ONYX, an industrial-grade metal 3D printer that succeeds the EOS M400-4. The new machine, along with a host of software upgrades and integrated peripherals—including the new RFS Pro—unlocks higher productivity, reliability, and cost efficiency.

Building on the M400-4

Launched about a decade ago, the EOS M400-4 has become a staple for many industrial metal AM users, including Siemens Materials Solutions, Sintavia, TheSteelPrinters and more. According to EOS, the company currently has about 500 M400-4 systems installed in industries like space, aerospace, and energy. The EOS M4 ONYX builds on the successes of this existing industrial system, maintaining key elements like the footprint and layout of the machine, while integrating significant upgrades informed by user feedback.

As Sebastian Becker, EOS’ Head of Product Management Metal Solutions, explained to us: “We developed a successor machine to the M400-4—the EOS M4 ONYX—with the aim of really going deeper into industrial-grade quality and improving the return on investment for production.”

At first glance, there is an obvious difference between the M4 ONYX and EOS’ other metal AM systems: the machine is the first to have a dark color profile. As Becker sums it up: “it looks awesome.” The new color visually distinguishes the new machine as being on another level in terms of strength and productivity. “The design adjustment really shows that the new system has a stronger engine, which delivers a 50% reduction in total cost of ownership, a 50% increase in productivity, and a 30% utilization rate increase.” 

Improvements on all fronts

Driving the development of this new and improved system were three key goals: 

• To improve industrial viability
• To expand business cases through a stronger ROI
• To increase the scale of parts

Industrial-grade updates

For the first goal, Becker explains that EOS wanted to bring the new solution up to CNC standards in terms of homogeneity, as well as in terms of user experience. “This starts at data preparation and goes into the operation of the machine itself,” he says. 

On this front, the M4 ONYX integrates several upgrades, including homogenous gas glow and active temperature control, which ensure cleaner builds and shorter production cycles, as well as an integrated error detection system that can reduce quality assurance expenses by as much as 50%. This smart monitoring solution includes a new digital fingerprint tool that leverages optical tomography (OT) to capture images of each print layer and enables the visualization of grey value for each layer. This data then enables the generation of statistical control signatures, which can be used as a reference to define limits and identify if a print job has gone beyond these limits. If a print job does exceed the signature profile for a given part, the print job can be paused remotely to save time and powder.

Upping the ROI

In terms of improving the ROI and cost per part for end users, EOS has made a host of upgrades and integrations. Among them is a key feature of the EOS M4 ONYX: the six 400W lasers that operate simultaneously to increase print throughput by up to 50% and reduce part costs by 30%. 

Peripheral systems also contribute to greater productivity that drive a faster ROI. For example, the Grenzeback Dual Setup Station – EOS Edition, which comes integrated in the EOS M4 ONYX, automates job exchanges within the 3D printer, unlocking continuous production without the need for operator intervention. Becker elaborates: “The Setup Station has the main task of getting the hot build job out of the process chamber and moving it to a parking lot for the cool down period. This allows the second build job to be moved into the process chamber for an automatic start.” This ultimately boosts availability and utilization of the system since there is no operator needed and you don’t need to wait in between build jobs. In fact, the Duel Setup Station can reduce laser down times to under 60 minutes. 

The aim of these upgrades is to unlock new business cases and promote the increased adoption of EOS’ solutions in industries like automotive and consumer products. “With an affordable system CAPEX and productivity we’ve never seen before, we are opening up new business cases in industries we have today but also in industries we do not yet have,” Becker adds. 

Enlarged applications

The third goal is centered on unlocking larger applications. To this end, EOS has increased the build volume of the new metal AM hardware to 450 x 450 x 400 mm, adding 50 mm to both the x/y axes. “The build envelope can be a limitation in a lot of cases, so that’s why we increased the build envelope of the machine,” Becker says. 

The enlarged build area, along with other productivity improvements, will not only enable EOS to tap into new markets but also deepen its applications in existing markets. In the medical industry, for example, the EOS M4 ONYX could facilitate the production of use cases like knee implants, which had previously not been viable. 

Powder handling and recycling

EOS’ new M4 ONYX solution also introduces upgrades to powder workflows. Within the system’s architecture, the integration of the Volkmann Automated Powder Handling system offers scalable closed-loop powder management for continuous, cost-effective production. The system, customized for EOS hardware, comprises a reloading module that sits on top of the printer and feeds powder into the dispensing system when needed. The system also includes the Volkmann PowTReX system, which vacuums powder out of the Dual Setup Station and sieves it into a 100L tank at the bottom of the printer. Users also have the option of installing a separate 250L powder storage tank, which enables multiple machines to be integrated into the same closed loop cycle.

Also offered alongside the EOS M4 ONYX is the game-changing RFS Pro system, which reduces hazardous waste in the metal AM process by up to 90%, while also improving process productivity, safety, and sustainability. The system effectively removes powder particles and spatter that are blown away in the printing process and separates them into usable powder, spatter, and condensate. “The powder is still virgin and we can reuse it,” Becker elaborates. “The spatter is welded, and the condensate is super lightweight but it is pyrophoric, meaning it is really dangerous.”

It is this condensate that makes LPBF waste material considered hazardous and can increase health and safety risks for operators. “What we are doing in our RFS Pro filtration system—and this is really a world premiere—is to separate the powder using gravity. This separates the powder from the lightweight condensate, with 90% of the powder being collected in a bin for reuse or recycling, while the other 10% (the condensate) is filtered and oxidized before being secured in a waste bin.  This is now just 10% waste instead of 100% and it is non-flammable waste.”

The RFS Pro therefore introduces significant benefits, like minimizing material waste significantly and thus saving on material costs, and creating a safer production environment for operators.

“At EOS, we live by our longstanding commitment to efficiency, safety, and innovation. Those pillars along with AM manufacturing innovations from partners like Volkmann and Grenzebach, have culminated in our most productive metal AM system to date,” adds Sebastian Becker. “Beyond the technical milestone of our RFS Pro, our customers will benefit from our deep collaborative relationships to successfully scale their AM production with confidence and consistency.”

Advances on the software front

The EOS M4 ONYX also benefits from a range of software updates that are geared towards greater process transparency, efficiency and stability. For instance, EOS’ solutions can be integrated with industry-ready APIs for more seamless integration into digital workflows (i.e. Siemens NX, CATIA, Autodesk Fusion). This can reduce order-to-print times by up to 30%. As mentioned earlier, the company’s new digital fingerprint system with statistical control can reduce quality assurance and non-destructive inspection efforts by up to 50%.

Becker also emphasizes the impact that EOS’ Smart Fusion and Smart Fusion Replay tools will have on the overall printing process. “Overheating is a typical product for DownSkins, so we are using OT cameras and sensors to gain insights on overheating in certain layers. If the part is too hot, then we can reduce the laser power in the next layer (by max 30%).” The Smart Fusion function results in overheating control and can also unlock faster print speeds, since supports will no longer be needed in these overheating areas. Smart Fusion Replay, for its part, enables users to freeze parameter sets and replay them on all production systems without having Smart Fusion active. 

EOS M4 ONYX FLX

The EOS M4 ONYX with six 400W lasers will become available in Q1 2026, while a second version of the printer, the EOS M4 ONYX FLX, will launch slightly later in Q3. This second light engine integrates four 1kW beam-shaping lasers, which offers the potential for even greater productivity, particularly for bulky components.

EOS has been working with nLight to integrate the latter’s unique laser technology into its production systems. In fact, the AMCM M 290 FLX became the first EOS 3D printer to use the beam-shaping technology, unlocking faster print rates for common powder feedstocks like 316L steel and aluminum. The EOS M4 ONYX FLX leverages nLight’s beam-shaping lasers that can widen laser spot shape from the standard gaussian 80 microns up to 250 microns. This is primarily beneficial for bulky parts. “If the user is printing heat exchangers with many thin walls, it might not make sense to go for the FLX system,” Becker explains. “However, if they are printing a bulky part, like an impeller made out of a nickel-based alloy, it would make sense.”

A Formnext 2025 debut

You can see the new EOS M4 ONYX at Formnext 2025 this week in Frankfurt. EOS can be found in Hall 11.1, booth D41. 

“At EOS, our customers have always been at the heart of every innovation. The launch of the EOS M4 ONYX is a testament to our legacy as pioneers in additive manufacturing and our commitment to empowering manufacturers worldwide,” concludes Marie Langer, CEO of EOS. “This optimized system was only made possible by the dedication and expertise of our global team, whose relentless pursuit of AM excellence continues to set new standards for the industry. Together, we are shaping the future of metal 3D printing productivity and responsible manufacturing, delivering the highest quality solutions for our customers.”