Stainless Steel 316L is a marine-grade stainless steel, 3D printed by DMLS, for parts that face salt air, chemicals and repeated washdowns. Its added molybdenum gives it strong resistance to chlorides, and it bends rather than cracks, absorbing impact and vibration. Printing turns valves, manifolds, static mixers and test fixtures with internal passages into single parts that are easy to clean. Marine, chemical processing, food production, power generation and aerospace teams use it, along with medical device teams for non-implant tooling and fixtures.
How Stainless Steel 316L is manufactured
Stainless Steel 316L is manufactured using Direct Metal Laser Sintering (DMLS) on EOS M 290 systems, an industrial powder-bed process in which a laser melts fine stainless steel powder layer by layer in an inert argon atmosphere. Precision F-theta optics keep the laser beam consistent across the entire build platform, and support structures anchor each part to the build plate. This allows complex geometries, internal channels and consolidated designs to be produced in one build, with repeatable quality from the first part to the last.
Upload CAD files to Forge Labs Steam for instant Stainless Steel 316L pricing and live manufacturability feedback, and fix issues before production.
Upload CAD files to Forge Labs Steam for instant Stainless Steel 316L 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.
EOS Stainless Steel 316L is a production-grade DMLS stainless steel for corrosion-resistant 3D printed parts in marine, chemical processing, food production, and industrial equipment programs. From valves and manifolds to enclosures, brackets, and flow components, 316L supports complex geometries while maintaining cleanability and consistent field performance in harsh environments.
Design teams rely on 316L where chloride exposure, washdown cycles, and long service life matter, and the alloy's ductility helps absorb impact and vibration without brittle failure. Its molybdenum content gives a pitting resistance equivalent (PREN) above 24, so it holds up in marine atmospheres and chloride waters.
It also serves pharmaceutical tooling and stainless emblems and trim, parts that need durable stainless performance without tooling lead times. Teams use Stainless Steel 316L to hold tight tolerances while reducing assembly complexity through consolidated part designs.
Forge Labs gives teams a reliable path from prototyping to repeatable production, with fast iteration across low- to mid-volume runs.
Aerospace MRO
Test fixtures with printed air passages and machined seal seats, one replacing three tools.
Aerospace
Combustor swirlers in runs of 35, a fuel-pump impeller and pitot rakes for test stands.
Clean Tech & Process
Helical static mixers up to 380 mm and threaded tees, each printed as one part.
Power Generation
Counterweights that keep their designed mass, and valve plates printed as modeled.
Medical & Healthcare
Surgical tooling and validation fixtures in a powder with ASTM F138 chemistry.
Aerospace MRO
Engine maintenance shops use Stainless Steel 316L for test plates and handheld air-test fixtures, where internal air passages, threaded ports and O-ring seals have to work together in one tough body. One printed fixture replaced three separate tools: its passages were printed in place, then bores, pipe threads and O-ring grooves were machined to the drawing, with seal faces finished to about 0.8 µm Ra. The finished body shipped within three business days of a successful print.
Aerospace
Propulsion developers order combustor swirlers in runs of 35, a radial fuel-pump impeller, and pitot rakes and their sheaths for test instrumentation, printed in DMLS alloys including 316L. Heat treatment, HIP and machining are available where the drawing calls for them. Of those alloys, 316L is the most ductile, with 41% elongation horizontally and 49% vertically as built.
Clean Tech & Process
Process equipment makers use DMLS 316L for helical static-mixer vanes up to 380 mm long with sanitary tri-clamp ends, and for tees with NPT threads and hose barbs. The internal geometry that makes a mixer work would need several machined and welded pieces; printed, it is one part. 316L resists phosphoric and acetic acids, caustic cleaning solutions and organic solvents, which suits reactor nozzles, valve bodies, spray nozzles and dairy or brewery fittings.
Power Generation
Power generation equipment makers use DMLS 316L for screw-in counterweights drawn in hot-rolled steel, and for valve plates and valve heads. 316L weighs about the same as the drawn steel, so the designed mass carries over, and the counterweight thread is cut after printing to mate with its piston. A valve plate was printed as modeled and sampled at ±0.3 mm with every reading passing, and the counterweights shipped with their aluminum pistons in 13 business days, on the promised date.
Medical & Healthcare
Medical device teams use Stainless Steel 316L for non-implant surgical tooling, handling fixtures, validation fixtures and cleanable process hardware for GMP environments. The powder chemistry corresponds to ASTM F138 (UNS S31673), and serialized lot and build traceability supports the device maker's pilot lots and qualification plans.
Values from the EOS StainlessSteel 316L-4441 datasheet for the EOS M 290 (40 µm), tested to the standard listed with each property. Modulus, hardness, surface roughness and thermal expansion come from EOS's 20 µm datasheets, and alloy constants EOS does not publish come from wrought 316L mill data.
Mechanical performance
Stainless Steel 316L delivers dependable strength with exceptional ductility, giving teams a proven DMLS baseline for chemical processing equipment, valves and precision mechanical assemblies. Its balanced mechanical profile handles demanding load conditions while preventing brittleness in critical applications, and its high elongation lets parts deform rather than crack under overload.
The values are for parts as built, with no heat treatment. The horizontal and vertical rows show the modest anisotropy of laser-melted stainless steel, so plan the load direction of critical features in parts that need precise geometry and tight tolerances.
Material makeup
Near-full density keeps critical features in tolerance and downstream finishing predictable, and the defect percentage shows how little porosity remains in the printed metal.
Surface roughness is given as built and after shot peening. Machining and polishing take sealing faces and cosmetic surfaces finer still, and 316L can be polished to a mirror finish for aesthetic applications.
Heat performance
Stainless Steel 316L suits chemical processing and food equipment that is heated, washed down and cooled. Its relatively high thermal expansion, which rises with temperature, matters where 316L mates with other metals or polymers.
Avoid long-term service in the carbide-precipitation range EOS lists, where carbides can form at the grain boundaries and reduce corrosion resistance. The melting range, conductivity, specific heat and oxidation limit support heat-transfer and high-temperature design.
Functional performance
Stainless Steel 316L conducts electricity, so parts can be grounded, but its resistivity is far higher than aluminum or copper, so it suits grounded housings, shielding features and fixtures rather than current-carrying parts.
The permeability row is for annealed wrought 316L, which is essentially non-magnetic, a useful property for instrument hardware near sensors.
Compatibility data
EOS publishes no chemical table for printed 316L, so the ratings come from wrought 316L corrosion data for the same alloy. It resists marine atmospheres, chloride waters, phosphoric and acetic acids, caustic cleaning solutions, organic solvents and food and dairy fluids, while hydrochloric acid and boiling strong caustic attack it, and permanent seawater immersion is not recommended.
Chemical ratings are screening guidance; confirm them with application-specific testing before production release.
Compliance
EOS states that the powder chemistry corresponds to ASTM F138 (UNS S31673), and its safety data sheet confirms the powder contains no REACH Annex XIV substances. EOS's datasheet for the alloy states that as-built tensile properties show the values of ASTM A403, a wrought fittings standard, so solution annealing is not necessary, and EOS lists heat treatment to AMS 2759 as optional.
Each status comes from EOS documents for the powder, so teams can start industrial qualification from supplier data. EOS does not develop or certify the powder as a medical device or for food contact, so the part owner validates those uses.
Datasheets, design guidance and supplier documentation for Stainless Steel 316L.
Access the most recent datasheet and supporting documentation maintained by our engineering team.
Stainless Steel 316L datasheetExplore printable geometry recommendations, wall thickness tips, and finishing playbooks for DMLS.
View DMLS design guide
Stainless Steel 316L is manufactured using Direct Metal Laser Sintering (DMLS) technology, providing high strength and precision for mission-critical applications. Dense tooling and end-use components print from a single prototype to repeat production batches.
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