Maraging Steel MS1 is a very high-strength tool steel, 3D printed by Direct Metal Laser Sintering (DMLS) for tooling and highly loaded parts. It machines easily straight from the printer, then heat treatment brings it to tool-steel hardness with almost no change in size. Printing lets cooling channels follow the shape of a mold cavity where drilled lines cannot reach, and cavities polish to a very fine finish. Toolmakers, aerospace, motorsport and power generation teams use it for injection mold inserts, forming tools and fixtures, and gearbox, suspension and valve parts.
How Maraging Steel MS1 is manufactured
Maraging Steel MS1 is manufactured using Direct Metal Laser Sintering (DMLS) on EOS metal systems, the industry benchmark for the process. Precision optics with f-theta lenses keep beam quality consistent across the entire build platform, and closed-loop powder handling and an inert atmosphere protect the steel as each layer fuses. After printing, the EOS solution anneal and aging cycle brings them to full strength and hardness, so complex internal features come out of one build ready for finishing.
Upload CAD files to Forge Labs Steam for Maraging Steel MS1 quotes and live manufacturability feedback, and fix issues before production.
Upload CAD files to Forge Labs Steam for Maraging Steel MS1 quotes and live manufacturability feedback, and fix issues before production.
DMLS parts generally exhibit a slightly rough, matte finish due to the laser sintering process, resulting in a uniform surface texture. While this natural finish is sufficient for many functional applications, Forge Labs offers several post-processing options to enhance aesthetics, accuracy, and performance.
Support structures are carefully removed, and parts undergo shot peening to create a uniform, matte surface and help relieve residual stresses. Critical features may receive light machining for tighter tolerances.
Precision machining and polishing processes enhance surface quality, achieving tighter tolerances and smoother finishes for critical applications.
Automotive-grade coating that enhances aesthetics and durability. Each part is hand-finished with professional-grade equipment for exceptional adhesion and custom color matching.
Maraging Steel MS1 combines exceptional hardness after heat treatment with superior dimensional stability during the aging process, and it machines well in both the as-built and heat-treated states. From rapid prototyping to production runs, teams rely on it to maintain tight tolerances while reducing assembly complexity through consolidated part designs.
Through EOS DMLS, Maraging Steel MS1 reaches tensile strength above 2,000 MPa after aging, enabling tooling and components that push the boundaries of mechanical performance. Its precipitation hardening mechanism delivers uniform hardness throughout complex geometries. Unlike traditional tool steels, maraging steel hardens through intermetallic precipitates rather than carbon, so parts reach full hardness through a simple thermal aging treatment.
Forge Labs' controlled aging process at 490 °C for 6 hours achieves consistent properties. Our machining capabilities enable hybrid approaches for critical tolerances, and complex internal cooling channels and conformal cooling designs print directly into the tool, reducing lead times compared to conventional tool manufacturing.
Beyond molds, Maraging Steel MS1 is used for precision cutting tools, dies, complex jigs and automotive production fixtures. Medical device manufacturers use it for production-line tooling, and aerospace and defense programs use it for high-performance mechanical components.
Tooling & Molding
Mold inserts with conformal cooling and only +0.1% dimensional change through heat treatment.
Aerospace
Forming tools, composite fixtures and high-load fittings with near-identical strength in every build direction.
Motorsport
Topology-optimized gearbox, suspension and hydraulic parts with 650 MPa heat-treated fatigue strength.
Industrial & Energy
High-pressure valve, pump and turbine parts that work up to about 400 °C.
Tooling & Molding
Toolmakers use Maraging Steel MS1 for injection mold inserts, extrusion tools and hot pressing tools. DMLS builds conformal cooling channels that follow the cavity surface where drilled lines cannot reach, and inserts harden with a typical dimensional change of only +0.1%. Cavities polish to a very fine finish for molded parts, and inserts can be machined, spark-eroded, welded and coated after aging.
Aerospace
Aerospace manufacturers use Maraging Steel MS1 for sheet metal forming tools and composite assembly fixtures, and for high-load structural fittings. Forge already prints engine test plates and maintenance fixtures by DMLS in 316L stainless steel, including a single tool that replaced three separate fixtures, with extra stock left on critical bores for machining to size. MS1 brings tool-steel hardness to the same approach, and after heat treatment its strength differs by less than 1% between the horizontal and vertical build directions.
Motorsport
Racing teams use Maraging Steel MS1 for ultra-high-strength components that survive extreme loads, including gearbox and suspension parts and high-pressure hydraulic fittings. Topology-optimized DMLS designs take weight out of highly stressed parts by removing material where it carries no load. After aging, its 650 MPa fatigue strength suits parts under cyclic load. Bearing seats and sealing faces are machined to size once the part is hardened.
Industrial & Energy
Heavy industry and power generation use Maraging Steel MS1 for high-pressure valve parts, pump and turbine components and heavy machinery parts that need ultra-high strength. Forge already prints valve plates, valve heads and seal protectors for power generation equipment by DMLS in 316L and 17-4 PH stainless steel, finishing grooves and threads by machining or wire EDM. MS1 is the higher-strength option for the same parts and works up to a maximum operating temperature of about 400 °C.
Values from EOS MaragingSteel MS1 datasheets for the EOS M 290 (40 µm), tested to the standard listed with each property.
Mechanical performance
Maraging Steel MS1 has the strength and hardness that injection molding tools and inserts, precision cutting tools and dies, and aerospace manufacturing tooling demand. Heat-treated values come first, the condition most tools and load-bearing parts are used in, followed by as-built values for parts that are machined before aging.
As-built parts show some anisotropy, which heat treatment reduces, so aged parts reach almost the same strength in every build direction. Hardness, fatigue and impact values describe the peak-hardness aging cycle, which maximizes strength and hardness at the expense of impact toughness; allow for this in parts that see sudden shock loads.
Material makeup
Near-full density and a very low defect level keep critical features in tolerance and downstream finishing predictable. The dimensional change row is the allowance to make when features are machined to size before heat treatment.
As-built surfaces suit functional faces, and shot peening evens them out; mold cavities and sealing faces are machined or polished to a fine finish. The minimum wall thickness sets the thinnest rib or vane the process resolves. The composition rows give the EOS alloy limits; with chromium far below the level that defines a stainless steel, MS1 needs oil, coating or dry storage to protect it from corrosion.
Heat performance
The maximum operating temperature is the service limit EOS gives for Maraging Steel MS1, high enough for mold inserts, hot pressing tools and industrial equipment near heat sources.
The solution anneal and aging values are the EOS heat treatment behind the heat-treated properties. Thermal conductivity rises after aging, which helps conformal-cooled inserts draw heat from the cavity, and the expansion coefficients for each temperature range let designers predict fits in hot tooling.
Compliance
EOS states that the chemical composition of MS1 corresponds to AMS 6514 18Ni300 and European 1.2709 (X3NiCoMoTi 18-9-5), so drawings that call out these grades can be checked against supplier data.
These entries describe chemistry rather than product certification, since AMS 6514 covers wrought bars and forgings. EOS does not develop or certify MS1 powder for medical devices or food contact, so it is used for tooling rather than parts that touch patients or food.
Datasheets, design guidance and supplier documentation for Maraging Steel MS1.
Access the most recent datasheet and supporting documentation maintained by our engineering team.
Maraging Steel MS1 datasheetExplore printable geometry recommendations, wall thickness tips, and finishing playbooks for DMLS.
View DMLS design guide
Maraging Steel MS1 is manufactured using Direct Metal Laser Sintering (DMLS) technology, providing high strength and precision for mission-critical tooling and end-use components.
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