--- title: "Reading a metal powder datasheet: the numbers that decide printability" description: What d10, d50 and d90 actually tell you, why oxygen content sets the ceiling on fatigue life, and which datasheet figures do not survive contact with your machine. image: https://www.ospreyatomiqs.com/hubfs/pexels-herry-11605271.jpg --- [Skip to content](https://www.ospreyatomiqs.com/newsroom/reading-a-metal-powder-datasheet#main-content) [![Osprey](https://www.ospreyatomiqs.com/hs-fs/hubfs/raw_assets/public/osprey/images/logo-white.png?height=160&name=logo-white.png)](https://www.ospreyatomiqs.com/) - [The platform](https://www.ospreyatomiqs.com/platform) - [Materials](https://www.ospreyatomiqs.com/materials) - [Industries](https://www.ospreyatomiqs.com/industries) - [Heritage](https://www.ospreyatomiqs.com/heritage) - [Company](https://www.ospreyatomiqs.com/company) - [Careers](https://www.ospreyatomiqs.com/careers) - [Newsroom](https://www.ospreyatomiqs.com/newsroom) [Contact](https://www.ospreyatomiqs.com/contact) [Speak to a metallurgist](https://www.ospreyatomiqs.com/contact) [Contact](https://www.ospreyatomiqs.com/contact) [Speak to a metallurgist](https://www.ospreyatomiqs.com/contact) Article 23 September 2026 6 min read # Reading a metal powder datasheet: the numbers that decide printability A powder datasheet is a specification, not a prediction. It tells you what a lot was measured to contain and how it behaved in a handful of standardised tests. It does not tell you how the powder will spread at 40 ... ![](https://www.ospreyatomiqs.com/hubfs/pexels-herry-11605271.jpg) A powder datasheet is a specification, not a prediction. It tells you what a lot was measured to contain and how it behaved in a handful of standardised tests. It does not tell you how the powder will spread at 40 microns on your machine, or what your part will do after ageing. Learning which numbers carry that information, and which only look as though they do, is most of what separates a confident material choice from an expensive one. Here is what to read, in the order it usually matters. ## Particle size distribution The distribution is normally given as three points: d10, d50 and d90. Ten per cent of the material by volume sits below d10, half below d50, ninety per cent below d90. The d50 is the number people quote and the least useful of the three. The tails are where the behaviour lives. Fines below roughly 10 microns agglomerate, hold moisture and raise the risk of spatter and recoater streaking. Coarse particles above the layer thickness cannot be packed into the layer at all, so they are either pushed along by the recoater or dragged into the part. Match the cut to the process rather than to the alloy: | Process | Typical cut | Why | | --- | --- | --- | | Laser powder bed fusion | 15 to 45 microns | Thin layers need fine, free flowing powder that still spreads evenly | | Electron beam powder bed fusion | 45 to 106 microns | Coarser powder resists charging and smoking under the beam | | Directed energy deposition and laser cladding | 45 to 150 microns | Powder must flow through a nozzle and survive the carrier gas | | Metal injection moulding | Below 22 microns | Fine powder drives green strength and sintered density | One caveat that costs people real money: the measurement method changes the answer. Laser diffraction (ISO 13320) and dynamic image analysis (ISO 13322-2) will report different d10 and d90 values for the same powder, because one infers a sphere from a scattering pattern and the other measures projected shapes. Sieve analysis differs again. Two datasheets are only comparable if they were produced by the same method, so check the method line before you conclude that one supplier's powder is finer than another's. ## Flow and packing Three numbers usually appear together. Apparent density (ASTM B212) is how much powder settles into a fixed volume under gravity. Tap density (ASTM B527) is the same volume after mechanical settling. Hall flow rate (ASTM B213) is the time for 50 grams to pass through a calibrated funnel, and a powder that will not flow at all is reported through the wider Carney funnel instead. The ratio of tap to apparent density, the Hausner ratio, is a quick read on cohesion. Below about 1.25 suggests a free flowing powder. Above 1.4 suggests one that will bridge and arch, which in a powder bed machine shows up as an uneven layer rather than as a blocked hopper. Be careful about reading Hall flow as spreadability. A funnel test measures flow under gravity through an orifice. A recoater spreads a thin layer under shear at speed, which is a different mechanical problem. Powders with very similar Hall times can behave differently on the same machine, which is why rheometry and, in the end, a trial build tell you more than the funnel does. ## Chemistry The alloying elements are given as a range, usually with a typical value. Read the range, because that is what the supplier is committed to. A part qualified against the typical value can drift when a later lot sits legitimately at the other end of the specification. The interstitials matter more than their size suggests. Oxygen and nitrogen are measured by inert gas fusion (ASTM E1019) and reported in parts per million. Oxygen forms oxide films on particle surfaces and ends up as inclusions in the part, where it reduces ductility and fatigue life well before it changes tensile strength. Powder gains oxygen every time it is handled, sieved and reused, so the value on the datasheet is a starting point that only moves one way. If a material specification sets an oxygen ceiling for the finished part, the incoming powder needs headroom below it, not a value at the limit. In maraging grades such as 18Ni300, better known by its European designation 1.2709, the point is sharper still. The alloy takes its strength from intermetallic precipitation during ageing at around 490 degrees Celsius, and it is deliberately close to carbon free. Oxide and nitride inclusions give cracks somewhere to start, and they do so in exactly the tooling applications, conformal cooling inserts and die components, where the part is cycled thermally for its whole life. ## Morphology Gas atomised powder is close to spherical, which is why it packs and flows well. Datasheets increasingly quote a sphericity or aspect ratio figure, and sometimes a satellite count. Satellites are small particles fused to larger ones during atomisation. They raise cohesion and coarsen the effective size at the same time. The defect worth asking about is not on most datasheets at all: gas porosity inside the particle, trapped when the atomising gas is captured by the solidifying droplet. It survives melting in some conditions and appears as spherical porosity in the finished part, which no process parameter will remove. Cross sectional analysis or computed tomography on the powder is the only way to see it, so ask whether it has been done. ## What the datasheet cannot tell you Four things, all of which decide outcomes: - **Lot to lot consistency.** A single certificate says nothing about spread. Ask for statistical data across lots, not one analysis. - **Reuse behaviour.** How the distribution and oxygen content move over ten or twenty cycles, with your sieve and your handling. - **Moisture and storage.** Fine powder picks up water from the air. How it was packed and how long it has been open changes how it spreads. - **Your machine.** Recoater type, layer thickness, gas flow and build volume all interact with the powder. Two printers of the same model can disagree. ## The questions worth asking When you are comparing two powders that look equivalent on paper, the useful questions are narrow: which method produced the size distribution, what is the oxygen content and how much headroom does it leave, how wide is the chemistry range against the specification you have to meet, and what does the supplier know about variation between lots. A supplier who can answer those directly is telling you something about their process control as well as their powder. Osprey publishes full data for every grade it makes, including the measurement methods behind each figure. If you are qualifying a material and need data the datasheet does not cover, [ask us](https://www.ospreyatomiqs.com/contact), and if you want to see the range first, the [materials](https://www.ospreyatomiqs.com/materials) pages are the place to start. [Article](https://www.ospreyatomiqs.com/newsroom/tag/article) [Back to the newsroom](https://www.ospreyatomiqs.com/newsroom) More from the newsroom ## [News 2026-09-24 Qualification programme expanded for space-grade alloys](https://www.ospreyatomiqs.com/newsroom/test-qualification-programme-expanded-for-space-grade-alloys) ## [Press release 2026-09-24 Osprey confirms quality and environmental certifications under independent ownership](https://www.ospreyatomiqs.com/newsroom/test-osprey-confirms-quality-and-environmental-certifications-under-independent-ownership) ![Osprey](https://www.ospreyatomiqs.com/hs-fs/hubfs/raw_assets/public/osprey/images/logo-white.png?height=160&name=logo-white.png) Osprey is an independent advanced materials platform — engineering the metallurgy, atomisation and material technologies behind next-generation manufacturing. ## Platform - [The platform](https://www.ospreyatomiqs.com/platform) - [Materials](https://www.ospreyatomiqs.com/materials) - [Industries](https://www.ospreyatomiqs.com/industries) ## Company - [Heritage](https://www.ospreyatomiqs.com/heritage) - [About](https://www.ospreyatomiqs.com/company) - [Newsroom](https://www.ospreyatomiqs.com/newsroom) - [Careers](https://www.ospreyatomiqs.com/careers) ## Contact - [Enquiries](https://www.ospreyatomiqs.com/contact) - [Technical](https://www.ospreyatomiqs.com/contact) - [Media](https://www.ospreyatomiqs.com/contact) © 2026 Osprey. All rights reserved. Trusted. Proven. Dependable. ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Test Author", "url" : "https://www.ospreyatomiqs.com/newsroom/author/test-author" }, "dateModified" : "2026-09-24T14:16:25.868Z", "datePublished" : "2026-09-23T12:39:46.000Z", "headline" : "Reading a metal powder datasheet: the numbers that decide printability", "image" : [ "https://www.ospreyatomiqs.com/hubfs/pexels-herry-11605271.jpg" ], "mainEntityOfPage" : { "@id" : "https://www.ospreyatomiqs.com/newsroom/reading-a-metal-powder-datasheet", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://www.ospreyatomiqs.com/hubfs/logo.png" }, "name" : "Osprey Atomiqs" } } ``` ```json { "@context" : "https://schema.org", "@type" : "Organization", "description" : "Osprey is an independent advanced materials platform — engineering the metallurgy, atomisation and material technologies behind next-generation manufacturing.", "foundingDate" : "1974", "name" : "Osprey", "url" : "" } ``` ```json { "@context" : "https://schema.org", "@type" : "NewsArticle", "dateModified" : "2026-09-24", "datePublished" : "2026-09-23", "headline" : "Reading a metal powder datasheet: the numbers that decide printability", "image" : "https://149336906.fs1.hubspotusercontent-eu1.net/hubfs/149336906/pexels-herry-11605271.jpg", "mainEntityOfPage" : "https://www.ospreyatomiqs.com/newsroom/reading-a-metal-powder-datasheet", "publisher" : { "@type" : "Organization", "name" : "Osprey" } } ```