What Materials Can the EOS M 400-4 Print?

Direct answer: EOS currently lists M 400-4 processes for three aluminum grades, one case-hardening steel, seven nickel alloys, four stainless steels, four titanium grades and maraging steel MS1. EOS also says an M 290 process can be transferred to the M 400-4 for equivalent part properties, but that sentence is not permission to load every M 290 powder or copy a parameter file. The exact powder, released transfer package, layer process, software state and four-laser production qualification still have to match the installed system and part.

The useful decision is not simply whether four 400 W lasers can melt a metal. It is whether EOS has a current process route for the exact material and whether the organization can qualify that route across the M 400-4's four scan fields, 50 mm overlap zones, powder lifecycle, inert-gas environment, downstream processing and finished-part acceptance.

EOS M 400-4 material compatibility at a glance

What the exact EOS page establishes

The current EOS M 400-4 page identifies a 400 × 400 × 400 mm laser powder bed fusion system with four 400 W Yb-fiber lasers, four F-theta lenses and four scanners. EOS says each laser works over a 250 × 250 mm area with 50 mm overlap. The page then pairs each listed material with one or more layer thicknesses.

Those pairings are manufacturer process routes, not a free menu of layer heights. AlSi10Mg is listed at 40 and 80 µm; IN625 at 80 µm; PH1 at 20, 40 and 80 µm; and TiCP Grade 2 at 30 µm. Confirm the exact EOS material designation, layer process, machine and software generation, build plate, atmosphere and downstream state in the quotation and controlled work instruction.

The broader EOS metal-material portfolio is useful for finding grades and datasheets, but portfolio membership alone is not M 400-4 support. The exact model page and a current written EOS release for the installed system are the stronger sources.

The M 290 transfer statement needs a release, not an inference

EOS states that any M 290 process can be transferred to the M 400-4 to achieve equivalent part properties. That is meaningful manufacturer guidance, but its scope matters. It does not identify every transferred process on the public M 400-4 list, promise that every legacy or 1 kW M 290 route is installed, or qualify the customer's geometry.

For a grade absent from the visible M 400-4 list, ask EOS to identify the exact M 290 source process, M 400-4 transfer package, supported layer thickness, powder specification, software and parameter version, machine options, post-processing condition and property basis. Preserve that release with the production record. Do not infer support from laser wattage, a matching chemistry or a datasheet written for a different machine.

The EOS M 290 material guide is useful for seeing that machine's broader current list and its separate 400 W versus 1 kW copper boundary. It is not a substitute for M 400-4 confirmation. A route marked for a distinct M 290 configuration should not silently become a four-laser M 400-4 route.

Four lasers create a production qualification decision

The M 400-4's main distinction is not a new alloy family; it is four lasers sharing a larger build field. EOS markets higher productivity and says transferred M 290 processes can achieve equivalent part properties. Treat both as scoped manufacturer claims. Actual output depends on geometry, packing, supports, scan assignment, recoating, layer process, thermal history, maintenance, gas flow, software and acceptance criteria.

Parts or critical features that cross scan-field and overlap regions need a documented strategy and evidence suitable for the application. Define whether validation coupons, witness specimens or representative parts must sample different build locations and laser assignments. Review dimensional results, density or defect inspection, surface, microstructure and mechanical properties at the level required by the responsible quality plan. Do not advertise a universal four-times throughput, seamless overlap or equivalent-property guarantee from the product-page wording alone.

Aluminum, nickel and stainless routes still need exact end states

Al2139 AM, AlSi10Mg and Constellium CP1 are not generic interchangeable aluminum. Start with service temperature, strength, elongation, fatigue, corrosion, joining and finish, then select the exact EOS process and post-build state. Record whether acceptance is as-built, stress-relieved, heat-treated, HIPed, machined or coated.

The nickel list spans HAYNES 282, HX, IN625, IN718, IN718 API, IN939 and K500. A familiar superalloy name does not approve a turbine, combustor, pressure part, downhole tool or chemical-service component. Define temperature, dwell, cycling, stress, pressure and medium, then connect the released process to heat treatment, HIP, machining, internal-channel cleaning, surface and inspection.

Likewise, 17-4PH, CX, 316L and PH1 do not grant corrosion, passivation, food-contact, medical, pressure-code or fatigue compliance. The responsible organization must qualify the exact printed and finished condition under the applicable rules.

Titanium, case-hardening steel and MS1 need controlled downstream work

EOS lists Ti64, Ti64 Grade 23, Ti64 Grade 5 and TiCP Grade 2. Keep powder oxygen history, segregation, recovery, atmosphere, heat treatment, surface and inspection specific to the chosen process. Grade names that sound similar should not be collapsed into one titanium recipe, especially for fatigue-sensitive or regulated uses.

CaseHardeningSteel 20MnCr5 and MaragingSteel MS1 depend heavily on thermal state. Define case depth or aging condition, hardness, toughness, distortion, machining allowance and wear acceptance. Put datums, sealing faces, gear features, threads, bearing seats and critical holes on a controlled post-thermal machining and metrology plan.

Powder, inert gas, electrical and facility safety boundaries

The M 400-4 is industrial metal-powder laser equipment, not a desktop printer. EOS lists a roughly 4,900 kg machine, three-phase 50 A supply, compressed air and a recommended installation envelope larger than the machine. Site planning must follow current EOS installation, operating, maintenance and safety instructions; alloy-specific safety data sheets; local electrical, fire, ventilation and building requirements; trained personnel; and a site-specific risk assessment. Keep guarding, enclosure and interlocks intact.

Fine metal powder can create inhalation, eye, skin, contamination, combustible-dust and reactive-metal hazards. Inert process gas can displace oxygen. Condensate, filters, sieving residue and cleanup waste can retain hazards. Use EOS-approved closed handling, compatible conductive equipment, grounding and bonding, housekeeping, vacuuming, storage and waste routes; prescribed PPE; oxygen monitoring where required; and fire controls chosen with EOS and the local authority having jurisdiction. Water or an ordinary extinguisher can be wrong for some metal-powder incidents.

Ventilation must control the tasks identified by the current SDS and risk assessment, including loading, sieving, depowdering, sampling, filter changes, spills, cleanup and maintenance. NIOSH's safe 3D-printing guidance supplies a useful hierarchy-of-controls framework, but it does not replace EOS instructions, an industrial hygienist, the fire authority or the responsible EHS team. GoodPrints is not the final safety authority.

Powder lifecycle and changeover are part of compatibility

Preserve powder supplier and lot identity, certificate and SDS, receiving condition, sealed storage, exposure history, sieving, recovery, refresh or reuse rule, sampling, labeling, segregation and disposal under the released EOS process and quality plan. Do not invent a universal reuse count. Material changeover needs the manufacturer-approved cleaning and segregation procedure plus acceptance criteria; cross-contamination can alter chemistry, flow, optical behavior or customer compliance even when a build looks normal.

Post-processing and inspection complete the material route

A successful build is not a finished material result. Supports, stress relief, heat treatment, HIP, depowdering, machining, surface finishing, cleaning and inspection can control usable properties and dimensions. Internal passages need a defined powder-removal and verification route. Critical surfaces need machining allowance and metrology suited to the geometry.

Preserve traceability for machine serial number, maintenance and calibration state, software and process version, laser assignment, powder lot and history, build plate, orientation, support plan, atmosphere record, post-processing and inspection. Pressure, lifting, flight, vehicle-control, medical, food-contact, electrical, fire-rated and other high-consequence uses require their own applicable standards and responsible approval.

Unsupported feedstocks and better-fit paths

Custom powders, third-party blends, recovered powder outside the released route and grades absent from both the exact page and a written transfer package are poor fits by default. Particle distribution, morphology, flow, absorptivity, oxygen and contamination history matter alongside chemistry. For another industrial LPBF comparison, use the DMP Flex 350 Triple material guide. Wire-fed deposition belongs to a system such as the Meltio M600. Choose by the complete process chain, not the generic label "metal 3D printer."

Buyer and owner decision

• Choose the M 400-4 when an exact listed or currently released transferred process serves a recurring production family and the organization can qualify the four-laser build field plus the complete powder, gas, safety, downstream and quality system.
• Pause for written EOS confirmation when the grade, layer process, transfer package, machine option or software state is absent or ambiguous.
• Choose a smaller single-laser route when development volume does not justify four-laser field qualification or the current released process exists more cleanly on another EOS system.
• Choose a different platform when the required feedstock is filament, wire, pellet, resin, paste, ceramic slurry or an unqualified powder.
• Outsource first when demand is intermittent or the team cannot own industrial powder handling, gas, fire controls, downstream work, inspection and quality responsibility.

For a defined part, start with the material-selection checklist, review the custom-printing service FAQ, request a GoodPrints quote, or use the JC Print Farm route when external production is a better fit than owning the cell.

Bottom line

The EOS M 400-4 supports a real current portfolio across aluminum, case-hardening steel, nickel alloys, stainless steels, titanium and maraging steel, but compatibility is an exact process-and-production-system decision. Use the public exact-page list as the clean starting set. Treat the broader M 290 transfer statement as a manufacturer confirmation path, not an inferred hidden menu. Buy or schedule the machine only when the exact powder and layer process, four-laser field qualification, powder and gas controls, post-processing and finished-part evidence are all owned.

Official sources checked

• EOS M 400-4 product page for current model identity, four-laser/build-field data, exact listed materials and layer processes, and the M 290-transfer statement.
• EOS metal-material portfolio for current material-family and datasheet discovery context only, not inherited exact-machine support.
• NIOSH: Approaches to Safe 3D Printing for source-control and exposure-reduction boundaries.