For a general fabrication buyer, the right starting point is not the brand name but the production route plus a documented particle size distribution, since route controls sphericity, oxygen pickup, and apparent density, and those three parameters govern flow in the die or recoater [S2][S3]. This article maps the four routes to the alloys most engineers actually specify, then lines up the material families against four decision criteria: cost per kg, conductivity, corrosion resistance, and operating temperature window.
Four production routes and what each one actually delivers
Gas atomization, including Vacuum Induction Gas Atomization (VIGA), produces spherical or near-spherical particles with controlled size distribution and high apparent density, the geometry LPBF, EBM, and DED recoaters need to spread a 20 to 80 micrometer layer uniformly [S2][S3]. Water atomization is cheaper per kg and yields irregular particles that press-and-sinter well, but the higher surface oxygen and irregular shape rule it out for most laser bed fusion of reactive alloys [S3].
Solid-state reduction works on selected ores (notably iron and tungsten), crushing, mixing with carbon, then reducing in a continuous furnace to leave a sponge cake that is crushed, magnetically separated, and sieved; this is the dominant route for sponge iron powder used in structural PM parts and is also applied to tungsten for hardmetal tooling [S5]. Electrolysis deposits high-purity dendritic copper and iron powders at the cathode, valued where conductivity and low impurity matter more than price, while chemical reduction (hydrogen or carbon monoxide reductants on metal oxides) yields ultra-fine, high-purity powders of reactive metals such as cobalt, nickel, and tungsten compounds [S3][S5]. Mechanical milling sits alongside as a secondary route that can mechanically alloy, but it work-hardens the powder and introduces attritor-media contamination, so it is rarely the first choice for finished structural parts [S3].
Stainless, copper, nickel, iron: the press-and-sinter core
Sintered stainless steel (pre-alloyed with chromium) operates from roughly -161 °C up to about 870 °C depending on grade, takes impregnation for self-lubrication, and is the workhorse for medical device components, automotive parts, complex telecom geometries, and industrial gears [S1]. Copper powder, often alloyed with zinc, tin, or nickel, is the default when electrical or thermal conductivity is the design driver and the geometry is bearings, bushings, heat sinks, or small motor parts; its non-magnetic behaviour matters in contact assemblies where stray fields would be a problem [S1].
Nickel powder brings high-temperature strength and corrosion resistance, nickel steel is the cost-down structural choice for magnetic or higher-strength PM parts, brass cuts cost in low-load decorative or conductivity-peripheral parts, and elemental iron is the high-volume baseline for pressed components where the part is mainly a geometric carrier [S1]. Sinter-hardened materials, where the part is alloyed to achieve martensitic or bainitic structures during the cooling stage of sintering, are used when a buyer wants hardness in the 30 to 45 HRC range without a secondary heat-treat step [S1]. For buyers who want a broader catalogue view, the [metal powder](metal-powder) entry at SourceBySpec covers the same families in a process-agnostic format, and the [metal material](metal-material) page links the powder grades back to their bulk metallurgy equivalents.
LPBF and DED grades: 316L, 17-4PH, H13, maraging 18Ni300, Ti6Al4V
For powder bed fusion, the spec conversation shifts to oxygen content (typically under 0.1 wt% for titanium, under 0.05 wt% for the most demanding aerospace Ti6Al4V lots), Hausner ratio below about 1.25 for reliable recoating, and a documented D10/D50/D90 across a 15 to 63 micrometer window depending on the OEM [S2]. H13 tool steel powder is specified for conformal cooled inserts, mold inserts, and high-wear fixtures, where the as-built hardness and the ability to take a polish and EDM finish cut cycle time versus a machined tool [S2].
Maraging 18Ni300 (also sold as M300) is the dominant age-hardenable AM steel, chosen where post-build aging delivers yield strength around 1900 to 2000 MPa and very low distortion during the low-temperature aging step [S2]. Titanium Ti6Al4V (grade 5 in the wrought equivalent) is the aerospace and medical implant default, with a density near 4.43 g/cm³ and a strength-to-weight ratio that drives most airframe bracket and orthopedic implant bids [S2]. 316L stainless serves medical and marine LPBF work, 17-4PH serves parts that need post-build H900 or H1025 aging, and Inconel 718 or Haynes 282 serve hot-section aero and energy work where oxidation resistance above 650 °C is the gate [S2]. Buyers cross-shopping these grades against newer material options should also look at the [powder new material](powder-new-material) encyclopedia page, which tracks aluminum alloys such as AlSi10Mg and Scalmalloy alongside the titanium and nickel families.
Particle size, flow, and oxygen: the three numbers that decide printability
Particle size distribution is the single most quoted number on a powder certificate, because the recoater or feed system rejects lots that fall outside the printer's PSD band [S2]. Sphericity, usually reported as aspect ratio from image analysis, sits above 0.9 for premium gas-atomized lots and drops toward 0.7 to 0.85 for water-atomized or milled powders, which is fine for a die-fill but unacceptable for LPBF [S2][S3].
Apparent density (Hall flow, ASTM B212) and tap density (ASTM B527) feed into the Hausner ratio (tap/apparent); values below roughly 1.25 indicate a freely flowing powder, values above 1.4 indicate a lot that will bridge in the recoater and produce density defects in the build [S2]. Oxygen and nitrogen content are reported in weight percent and are the leading cause of rejected lots for titanium and aluminum, where each 0.01 wt% of excess oxygen shifts the fatigue curve measurably [S2]. For buyers who also touch press-and-sinter work, the same lot may pass the LPBF spec while failing a press-and-sinter green-strength requirement, because die compaction wants irregular particles with high surface area to lock under compaction pressure [S1][S3].
Selection criteria: cost, conductivity, corrosion, temperature
For a general fabrication buyer, four decision criteria usually settle the material before any brand conversation: cost per kg landed at the dock, electrical or thermal conductivity, corrosion resistance in the service environment, and the operating temperature window the part will see in service [S1]. Iron and nickel steel are the cheapest structural PM grades and dominate automotive press-and-sinter parts, copper and copper alloys cost more per kg but buy conductivity and non-magnetic behaviour, stainless 300-series adds corrosion resistance at a moderate premium, and nickel-based superalloys and titanium sit at the top of the cost stack while opening the temperature and strength envelope [S1][S2].
On a four-criteria comparison, press-and-sinter iron scores best on cost but lowest on conductivity and corrosion, sintered 316L stainless scores well on corrosion and temperature but mid-pack on cost, copper powder scores best on conductivity and lowest on strength-per-cost, and Inconel 718 or Ti6Al4V AM powder scores best on temperature and strength but worst on cost-per-kg [S1][S2]. The decision usually reduces to whether the geometry requires a press-and-sinter route, where a 4 to 6 dollar per kg iron or nickel-steel grade is realistic, or an AM route, where a 30 to 400 dollar per kg Ti6Al4V or Inconel 718 grade is normal, and the build volume and post-processing burden justify the delta [S2].
Real use cases and where each route fails
Press-and-sinter stainless is the standard for medical device brackets, automotive sensor rings, telecom shields with complex internal geometry, and industrial gears where the 96% to 99% theoretical density envelope is acceptable [S1]. Copper PM is the standard for self-lubricating bearings and bushings, heat-sink inserts, and small motor components where conductivity and the ability to impregnate with oil both matter [S1].
LPBF H13 is used for conformal-cooled plastic injection mold inserts that cut cycle time by 20% to 40% versus machined tooling in published case studies, and maraging 18Ni300 is used for aerospace structural brackets and tooling where post-build aging drives the strength without distortion [S2]. Ti6Al4V LPBF is used for patient-specific orthopedic implants and aerospace brackets where the buy-back on part count and weight pays for the powder [S2]. Failure modes to plan for: water-atomized powders in a LPBF machine produce lack-of-fusion defects, titanium powder stored open to air for more than a defined sieve cycle can drift above the oxygen ceiling, and copper-graphite mixes need controlled atmosphere sintering to avoid decarburization, all of which the buyer's incoming-lot inspection needs to verify [S1][S2][S3]. For related reference material on adjacent material specs, see the [sputtering target](sputtering-target-selection-a-spec-map-for-process-engineers) article, since sputter targets overlap with high-purity PM processes.
Track these signals over the next buying cycle: sieve and Hall-flow re-test results on every lot, oxygen/nitrogen analysis on every titanium and nickel-based shipment, and a documented reuse strategy (typically 5 to 10 cycles for titanium with refresh powder top-up, fewer for aluminum and reactive alloys) before lot retirement. Sourcing teams should also watch the [molybdenum](sourcing-molybdenum-from-china-spec-map-for-2026-industrial-buyyers) reference, since Mo and W PM supply chains share the same solid-state reduction and chemical reduction routes and frequently move together.
Component reference pages worth checking: metal powder, metal material, and metal curtain wall panel.
Related analysis: Height Gauge Sizing and Selection: Range, Accuracy, and Readout Map.