316L Austenitic Stainless Steel

Material Profile: 316L Austenitic Stainless Steel for Binder Jetting

Binder Jetting Engineering Material Technical Report Series

Compiled from manufacturer technical datasheets and peer-reviewed literature

Abstract—316L austenitic stainless steel (UNS S31603) is the workhorse corrosion-resistant alloy of metal binder jetting, qualified across all three Desktop Metal product lines (Studio System BMD, Shop System binder jet, Production System P-50, X-Series InnoventX/X25Pro/X160Pro). The 'L' grade (≤ 0.030 wt% C) is essential for BJ because the post-sinter cycle at 1340–1380 °C for several hours would otherwise sensitise standard 316 by Cr-carbide grain-boundary precipitation. As-sintered properties already meet ASTM A276 / A479 specifications: UTS ≈ 560 MPa, yield ≈ 220 MPa, elongation ≥ 50 %. Solution annealing per ASTM A403 is optional. Binder-jet 316L parts are preferred over laser-PBF 316L when cost-per-part dominates and complex internal channels (e.g. heat-exchangers, fluid manifolds, hygienic-design food/pharma equipment) cannot be machined economically.

Index Terms—additive manufacturing, binder jetting, 316L, austenitic stainless steel, Desktop Metal, UNS S31603, ASTM F3184.

I.  MATERIAL IDENTIFICATION

This section establishes the canonical names and commercial designations under which the material is supplied.

A.  Designation

Trade names: Desktop Metal 316L (Shop / Production / X-Series); ExOne 316L; Digital Metal DM 316L; HP Metal Jet 316L. Wrought equivalents: ASTM A276 / A479 / A480 (UNS S31603), AISI 316L, EN 1.4404 (X2CrNiMo17-12-2), W.Nr. 1.4404. AM-specific specification: ASTM F3184-16 (powder-bed fusion 316L).

B.  Full Chemical Name

Low-carbon austenitic FCC chromium-nickel-molybdenum stainless steel. Composition (wt%): Cr 16–18, Ni 10–14, Mo 2.0–3.0, Mn ≤ 2.0, Si ≤ 1.0, P ≤ 0.045, S ≤ 0.03, N ≤ 0.10, C ≤ 0.030, Fe — balance. Single-phase austenite (γ-Fe FCC) at room temperature; non-magnetic. The Mo addition over standard 304/304L raises pitting resistance equivalent number (PREN ≈ 26).

C.  Aliases and Alternative Designations

II.  COMPOSITION AND MOLECULAR STRUCTURE

A.  Empirical Chemical Formula

Fe(balance) — Cr(16–18%) — Ni(10–14%) — Mo(2.0–3.0%) — Mn(≤2%) — Si(≤1%) — C(≤0.03%, the 'L' = low-carbon). Single-phase γ-Fe FCC austenite; non-magnetic; PREN ≈ 26.

Fig. 1.  Repeating unit / structural schematic of the polymer matrix.

Fig. 2.  Schematic of the single-phase polymer (no reinforcement).

B.  Composition Breakdown

TABLE I
 COMPOSITIONAL BREAKDOWN OF 316L SS (DESKTOP METAL SHOP SYSTEM) (TYPICAL / PER SUPPLIER DATASHEET)

III.  MECHANICAL PROPERTIES — XY BUILD DIRECTION (HORIZONTAL)

In the XY orientation the tensile load is applied parallel to the powder-bed plane. Binder-jetted (BJ) parts in the as-sintered state generally show modest in-plane vs build-axis anisotropy because sintering occurs near the solidus and re-distributes the porosity left by the binder-removal step. For metal BJ, post-sintering treatments (HIP, solution-anneal, age) are commonly applied to bring properties to wrought-equivalent and to eliminate residual closed porosity.

TABLE II
 MECHANICAL PROPERTIES — XY ORIENTATION (316L SS (DESKTOP METAL SHOP SYSTEM))

IV.  MECHANICAL PROPERTIES — Z BUILD DIRECTION (VERTICAL)

In the Z orientation the tensile load is applied perpendicular to the printed layers. Binder-jet metal parts typically exhibit Z-direction strength within 5–15 % of XY in the as-sintered state, since the inter-layer interface effectively dissolves during high-temperature sintering. For sand-mould materials, Z-direction strength is dominated by inter-layer binder bonding and is generally 60–90 % of XY in transverse strength.

TABLE III
 MECHANICAL PROPERTIES — Z ORIENTATION (316L SS (DESKTOP METAL SHOP SYSTEM))

Binder-jet 316L has near-isotropic mechanical properties because the high-temperature sinter (~1380 °C) fully recrystallises the FCC austenite and eliminates inter-layer interfaces. This contrasts with laser PBF 316L which retains a columnar dendritic structure aligned with the build direction, producing 10–15 % anisotropy. Solution annealing per ASTM A403 (1050 °C / 1 h, water-quench) is optional for binder-jet 316L since as-sintered properties already meet ASTM A276 / A479.

V.  RECOMMENDED PROCESS PARAMETERS

Values summarised below give consensus operating windows from public datasheets (Desktop Metal, ExOne, voxeljet, cprint3d). Specific machines and parameter sets may differ within ±10 %; the supplier's verified parameter sheet always supersedes this table. For metal binder jetting, complete green-state cure (~200 °C) and a high-temperature de-bind / sinter cycle (typically 1 100–1 380 °C in H₂ / Ar / vacuum) are mandatory after print. For sand binder jetting, parts are usable directly after print (with optional microwave or oven post-cure).

TABLE IV
 RECOMMENDED BINDER-JETTING PROCESS PARAMETERS FOR 316L SS (DESKTOP METAL SHOP SYSTEM)

VI.  GLASS TRANSITION TEMPERATURE (TG)

Reported / typical Tg: Not applicable (metallic alloy).

Critical thermal limits: sensitisation window 427–816 °C (Cr-carbide grain-boundary precipitation — avoid prolonged exposure unless solution-annealed); creep limit ≈ 800 °C; melting range 1380–1400 °C.

VII.  HEAT DEFLECTION TEMPERATURE (HDT)

Heat deflection temperature is the temperature at which a standard bar deflects 0.25 mm under a specified flexural load (ASTM D648 / ISO 75).

TABLE V
 HEAT DEFLECTION TEMPERATURE OF 316L SS (DESKTOP METAL SHOP SYSTEM) UNDER STANDARD TEST LOADS

VIII.  DISTINGUISHING CHARACTERISTICS AND STANDARDS

A.  Universal corrosion resistance

316L's 16–18 % Cr forms a passive Cr₂O₃ surface layer; the 2–3 % Mo provides best-in-class pitting and crevice corrosion resistance in chloride media. PREN ≈ 26–28, vs ~18 for 304L. Ideal for marine, biomedical short-term implants, food/pharma processing, and chemical-handling equipment.

B.  Best-in-class ductility

Elongation at break ≈ 50 % even in as-sintered condition makes 316L the most forgiving binder-jet metal for crash-loaded or impact-handling components. Z-direction elongation is often higher than XY (due to recrystallised columnar grain alignment with load axis) — atypical compared to laser PBF behavior.

C.  Cost advantage at scale

Per-part cost on Production System P-50 is ~1/10 of laser PBF for production volumes ≥ 100 parts. The 12 000 cc/h jetting rate of P-50 enables hundreds of nested 316L parts per build — economic beyond traditional MIM tooling break-even (typically 1000+ parts).

D.  Welds and machines like wrought 316L

BJ 316L parts can be TIG / MIG welded using ER316L filler, wire-EDM cut, machined with carbide tooling, electropolished or passivated per ASTM A967. Surface finish in as-sintered state is Ra 6–10 µm; electropolished surfaces achieve Ra < 0.4 µm.

E.  Non-magnetic

316L is non-magnetic in fully austenitic state — relevant for MRI-compatible medical devices, sensitive scientific instruments, and electromagnetic shielding. BJ 316L typically retains < 1 % volume fraction of ferromagnetic phases (verifiable by Feritscope).

IX.  REPRESENTATIVE APPLICATIONS

316L SS (Desktop Metal Shop System) is typically deployed in the following applications:

1)  Surgical instruments and short-term implants: Custom retractors, bone screws, drill guides — leveraging biocompatibility (ASTM F138), sterilizability, and AM patient-specific geometry.

2)  Food and pharmaceutical processing equipment: Aseptic-line valves, manifolds, flow distributors — electropolishability and chloride-cleaner resistance.

3)  Marine and offshore hardware: Pump impellers, valve bodies, fittings exposed to seawater — pitting/crevice resistance + weldability for repair.

4)  Heat exchangers: Lattice / micro-channel HX for chemical and pharmaceutical processes — chemical inertness combined with AM design freedom.

5)  Automotive and consumer goods: Custom exhaust components, decorative parts (wristwatches, eyewear), hygienic kitchenware.

X.  REFERENCES

[1]  Desktop Metal, “316L stainless steel — Material Data Sheet,” 2024. [Online]. Available: https://www.desktopmetal.com/resources/316l-stainless-steel

[2]  Desktop Metal, “CETIM Qualifies 304L and 316L Stainless Steel,” 2024. [Online]. Available: https://www.digitalengineering247.com/article/desktop-metal-cetim-qualify-304l-stainless-steel/materials

[3]  ASTM A276/A276M-17, “Standard Specification for Stainless Steel Bars and Shapes,” 2017.

[4]  ASTM A403/A403M-22, “Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings,” 2022.

[5]  ASTM F138-19, “Standard Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for Surgical Implants,” 2019.

[6]  ASTM F3184-16, “Standard Specification for Additive Manufacturing Stainless Steel Alloy (UNS S31603) with Powder Bed Fusion,” 2016.

[7]  ASTM E8/E8M-22, “Standard Test Methods for Tension Testing of Metallic Materials,” ASTM International, 2022.

[8]  ASTM B962-17, “Standard Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes' Principle,” ASTM International, 2017.

[9]  ASTM E18-22, “Standard Test Methods for Rockwell Hardness of Metallic Materials,” ASTM International, 2022.

[10]  ASTM F3318-22, “Standard for Additive Manufacturing — Finished Part Properties — Specification for AlSi10Mg with Powder Bed Fusion — Laser Beam,” ASTM International, 2022.

[11]  ISO/ASTM 52900:2021, “Additive manufacturing — General principles — Fundamentals and vocabulary,” ISO, 2021.

[12]  ISO/ASTM 52904:2024, “Additive manufacturing — Process characteristics and performance — Practice for metal powder bed fusion process to meet critical applications,” ISO, 2024.

[13]  MPIF Standard 35-MIM, “Materials Standards for Metal Injection Molded Parts,” Metal Powder Industries Federation, 2022 ed.

[14]  Desktop Metal, “Material Properties of Binder Jet Parts,” Desktop Metal Technical White Paper. [Online]. Available: https://www.desktopmetal.com/resources/material-properties-of-binder-jet-parts

[15]  Desktop Metal, “Why Binder Jetting?” Desktop Metal Application Note. [Online]. Available: https://www.desktopmetal.com/resources/why-binder-jetting-1

[16]  Desktop Metal, “Materials portfolio overview,” Desktop Metal product page. [Online]. Available: https://www.desktopmetal.com/materials/

(Image Souce : Forgelabs)