Stainless Steel 17-4 PH is a hardenable stainless steel, 3D printed by DMLS, for parts that need high strength and hardness with good corrosion resistance. Heat treatment after printing makes it stronger than common 300-series stainless steels, and it still resists corrosion in mild environments. Printing also makes shapes machining cannot, from mold inserts with cooling channels that follow the part to lightweight brackets that keep metal only where the load runs. Aerospace, tooling, power generation and process plant teams use it for brackets, mold inserts, valve parts and pump impellers.
How Stainless Steel 17-4 PH is manufactured
Stainless Steel 17-4 PH is manufactured using Direct Metal Laser Sintering (DMLS) on an EOS M 290, an industrial powder-bed process in which a laser melts fine stainless steel powder layer by layer in an inert argon atmosphere. Precision optics with an f-theta lens keep beam quality consistent across the entire build platform. This allows complex geometries, internal channels and consolidated designs that traditional manufacturing cannot produce, in a high-strength, hardenable stainless steel.
Upload CAD files to Forge Labs Steam for instant Stainless Steel 17-4 PH pricing and live manufacturability feedback, and fix issues before production.
Upload CAD files to Forge Labs Steam for instant Stainless Steel 17-4 PH pricing 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.
Stainless Steel 17-4 PH combines an exceptional strength-to-weight ratio with good corrosion resistance in mild environments, and it is heat treatable for optimized properties in demanding applications. From aerospace actuators to injection mold tooling, and from rapid prototyping to production runs, teams rely on Stainless Steel 17-4 PH to maintain tight tolerances while reducing assembly complexity through consolidated part designs.
This versatile material bridges the gap between austenitic and tool steels. Printed through EOS DMLS and heat treated, it exceeds the ASTM A564 H900 strength requirements by more than three standard deviations.
Solution annealing together with aging gives the printed alloy its full hardness and strength and eases the slight anisotropy of the as-built metal. Engineers can tailor properties from maximum strength to enhanced toughness through the aging temperature, based on application requirements. Parts can be machined, shot-peened and polished as built or heat treated.
Forge Labs offers complete heat treatment options including solution annealing and aging to achieve desired properties. Our validated processes ensure consistent hardness and strength throughout complex geometries.
Power Generation
Valve seal protectors and valve heads printed to shape and tapped, with one lot shipped 5 business days early.
Aerospace
Topology-optimized brackets and mechanism parts with near-identical strength in every build direction.
Automotive & Tooling
Mold cores and inserts with conformal cooling, hardened to 42 HRC in a stainless steel.
Energy & Process Equipment
Pump, valve and coupling parts in an alloy with a long service record in process plants.
Power Generation
Power generation equipment makers use Stainless Steel 17-4 PH for valve seal protectors and valve heads that are printed to shape, then tapped or given a machined thread. Forge Labs recommends 17-4 PH where a part needs hardness and strength once solution annealed and aged. A redesigned valve head moved from 316L to 17-4 PH as a solid pin on a filleted collar and was reordered in a larger lot with no tooling, and one lot of tapped seal protectors shipped 5 business days ahead of the promised date.
Aerospace
Aerospace teams use Stainless Steel 17-4 PH for brackets and mechanism parts that need high strength with moderate corrosion resistance. DMLS lets a bracket be topology optimized, keeping material only where load runs, so it weighs less than a machined equivalent. After H900 aging, horizontal and vertical tensile strengths are within about 0.4% of each other, so a bracket carries its load whichever way it is built.
Automotive & Tooling
Toolmakers and automotive suppliers use DMLS 17-4 PH for injection mold cores, cavities and inserts with conformal cooling channels that follow the part contour, a layout machining cannot produce. H900 aging hardens the steel to 42 HRC to resist wear, and heat treatment changes dimensions by only about 0.2%, so inserts hold their geometry. Unlike maraging tool steel, 17-4 PH is a stainless alloy, which suits tools exposed to moisture and cooling water.
Energy & Process Equipment
Stainless Steel 17-4 PH has a long service record in petrochemical, petroleum, paper and food processing plants, where pump impellers and valve parts need more strength than 300-series stainless steels can give. The aged condition decides how it handles chlorides: stressed at the seacoast, 17-4 PH aged at 552 °C (H1025) and above has gone more than 25 years without stress corrosion cracking, while H900 cracked within 68 days, so H900 stays out of wet chloride service.
Values from the EOS StainlessSteel 17-4PH datasheet for the EOS M 290, tested to the standard listed with each property. Alloy constants and corrosion data EOS does not publish come from ATI and AK Steel wrought 17-4 PH data.
Mechanical performance
Stainless Steel 17-4 PH delivers high strength and handles demanding load conditions. Its balanced mechanical profile keeps structural integrity under repetitive stress without turning brittle, which suits high-precision tooling and mechanical components, aerospace structural components and brackets, and high-performance automotive parts.
Read the H900 rows for parts that have been solution annealed and aged, which EOS requires for full hardness and strength; the as-built rows show the softer, more ductile state before heat treatment. Each strength row gives the horizontal (XY) and vertical (Z) values, so read the direction that carries load in the part.
Material makeup
Consistent density and surface quality keep critical features in tolerance and downstream finishing predictable. The defect percentage shows how little porosity remains in the printed metal, and the roughness rows describe shot-peened surfaces.
Heat treatment changes dimensions only slightly, so parts meet specifications after aging and assemblies fit and finish without secondary rework. The composition rows are the EOS powder limits, which match ASTM A564 Type 630.
Heat performance
Stainless Steel 17-4 PH maintains dimensional stability through temperature swings, making it a reliable option for aerospace and automotive programs that see repeated thermal cycling. Design to the maximum service temperature, the point up to which the alloy keeps its high strength.
In wrought practice, aging between 482 and 621 °C (H900 to H1150) sets the balance of strength and toughness; the table shows H900, the highest-strength condition. Thermal conductivity rises with temperature, which matters for mold inserts that draw heat out of the part.
Functional performance
Stainless Steel 17-4 PH conducts electricity, so it suits conductive housings, grounded fixtures and functional prototypes that interact with electrical systems, though its resistivity is far higher than aluminum or copper.
It is strongly ferromagnetic in every condition, so it holds on magnetic fixtures and can be used with magnetic sensors, but it is not a choice for non-magnetic hardware.
Compatibility data
The table gives AK Steel immersion corrosion rates for wrought 17-4 PH bar across the H925, H1025 and H1150 aged conditions, beside annealed Type 304. Lower is better. Where the range is wide, H1150 sits at the high end in sulfuric and hydrochloric acid and H925 in nitric acid. Use the rates for screening before application testing. Overall, its corrosion resistance is comparable to Type 304 in most media, better than the hardenable 400-series stainless steels and below 316L.
It resists rural and mild industrial atmospheres in every aged condition, while seacoast exposure brings light rusting and pitting and stagnant sea water causes crevice attack, so 316L is the better choice for marine parts.
Medical readiness
EOS states that part chemistry complies with ASTM A564 Type 630 and ASTM F899, the specification for wrought stainless steels for surgical instruments. EOS certifies each powder lot with an EN 10204 type 3.1 mill test certificate.
In EOS testing, as-built 17-4PH test cubes passed ISO 10993-5 cytotoxicity, a strong starting point for instrument and fixture reviews. EOS does not develop or certify the powder as a medical device, so the device maker qualifies each part for its use.
Datasheets, design guidance and supplier documentation for Stainless Steel 17-4 PH.
Access the most recent datasheet and supporting documentation maintained by our engineering team.
Stainless Steel 17-4 PH datasheetExplore printable geometry recommendations, wall thickness tips, and finishing playbooks for DMLS.
View DMLS design guide
Stainless Steel 17-4 PH is manufactured using industrial-grade DMLS technology, providing high strength and precision for mission-critical applications. An EOS M 290 production system prints dense tooling and end-use components, from a single prototype to repeat production batches.
Can't find the answer you're looking for? Reach out to our customer support team.
Upload your design and get an instant quote for Stainless Steel 17-4 PH parts.
Create an account to upload CAD
STEP, STL, OBJ, 3MF and IGES supported
