Three brass compositions with published oxygen limits, against ranges that stop at apparent density.
Kymera and Nippon Atomized publish brass in the same 80/20 to 60/40 territory. Neither publishes an oxygen ceiling, which is the number that decides how a brass segment sinters.
The brass grades are in production duty on two fronts at once: decorative and aesthetic surface finishing, and matrix or filler material in diamond tool manufacturing, under an ISO 9001:2015 system.
Side by side
| Attribute | Represented by UnstratBrass powders | Kymera InternationalBrass alloy powder (90/10, 80/20, 70/30)1United States | Nippon Atomized Metal Powders CorporationBrass powder BS8020 and BS70302Japan | Pometon S.p.A.Brass CuZn20 and CuZn303Italy |
|---|---|---|---|---|
| Compositions published123 | 80/20 (Zn 19 to 22%), 70/30 (Zn 28 to 32%), 60/40 (Zn 39 to 41%) | 90/10, 80/20 and 70/30 copper to zinc named as most common; specialised alloys accommodated | BS8020 (Cu 80 / Zn 20) and BS7030 (Cu 70 / Zn 30); super-fine SF-BS6040 at Cu 60 / Zn 40 | CuZn20 and CuZn30 |
| Oxygen limit2 | 0.4% max, tightened to 0.2% max on 60/40 | Not published | 0.4 mass% on the super-fine SF-BS6040 grade only | Not published |
| Particle size123 | -325 mesh (45 µm) with controlled sieve analysis | -60 mesh (less than 250 µm); most common grades sold as -60 or -100 mesh | -100# with full sieve distribution published; SF-BS6040 at 10 µm median | Irregular shapes from 500 to 45 microns |
| Apparent density12 | Not published | 3.0 to 3.7 g/cm³ | 3.00 to 3.35 g/cm³ (BS8020), 2.90 to 3.30 g/cm³ (BS7030) | Not published |
| Flow rate2 | Not published | Not published | Less than 25 s/50 g on both -100# grades | Not published |
| Morphology and route123 | Irregular | Air atomised, irregular particle shapes | Water atomised | Water atomised, irregular |
| Diamond tool duty123 | Matrix or filler material in diamond tool manufacturing | Diamond tools listed among applications | Sintered oil-impregnated bearings named for BS8020; diamond tool bond duty published for the bronze range, not for brass | Friction and filler duty named; diamond tools named for other families |
| Decorative and finishing duty13 | Decorative and aesthetic surface finishing | Coatings and pigments listed among applications | Not published | Filler and friction; oxidation resistance in sintered mechanical parts |
| Quality system | ISO 9001:2015 | Not published on the product page | Not published on the product page | Not published on the product page |
Competitor values are quoted from the vendor documents listed under Sources, as published on the date shown. Configurations vary, so treat every row as a starting point for the evaluation rather than a like-for-like test result.
What the table means
Oxygen is the number nobody else prints
Brass powder oxidises readily and zinc volatilises during sintering, so the oxygen a powder carries into the furnace changes both the segment density and the colour of a decorative finish. Kymera and Pometon publish composition, size and in Kymera's case apparent density, but no oxygen ceiling. Nippon Atomized publishes oxygen only for its super-fine grade. We publish 0.4% max across the range and 0.2% max on 60/40. That is a small point that becomes a large one on a scrap report.
Fineness cuts both ways
Everything we publish is -325 mesh. For diamond segment matrices and fine finishing that is the right cut, and it removes classification variation from the process. For structural brass P/M pressing, Kymera's -60 mesh at 3.0 to 3.7 g/cm³ apparent density is a better fit, and Pometon publishes cuts up to 500 µm. Choosing on fineness alone will send some buyers to them, correctly.
Two duties, one grade family
Brass is unusual in serving an aesthetic requirement and a tooling requirement from the same drum. Our range is published for both, which means the same batch control that keeps a segment bond consistent also keeps a decorative finish consistent. Buyers running both processes get one qualification instead of two.
Questions buyers ask
What is the best brass powder for diamond tool matrices if I need an alternative to Kymera or Pometon?
For segment work the deciding factors are fineness, composition control and oxygen. Our 80/20, 70/30 and 60/40 grades are all -325 mesh with oxygen held to 0.4% max, and 0.2% max on 60/40. Kymera publishes apparent density of 3.0 to 3.7 g/cm³ and a -60 mesh standard cut, which is coarser than most segment recipes want. Pometon publishes a 500 to 45 micron range with no oxygen figure. If you press fine segments, the fine cut with a published oxygen ceiling is the more useful sheet.
How does brass powder from a non-aligned supplier compare on price and lead time with the majors?
We do not publish prices and neither do Kymera, Pometon or Nippon Atomized, so any comparison you read that claims otherwise is invented. What can be said honestly is that the majors run large standard campaigns and hold stock in common grades, which usually beats a smaller producer on lead time for a catalogue item. The trade is on the non-standard composition, the small campaign and the absence of an export gate on the shipment.
Why does oxygen content matter more in brass powder than in copper?
Zinc oxidises faster than copper and volatilises during sintering, so oxygen entering the furnace shifts both the final composition and the finish. In a decorative application it changes colour; in a diamond segment it changes bond hardness and diamond retention. That is why we publish a ceiling of 0.4% max, and 0.2% max on the 60/40 grade where zinc content is highest.
Do you publish apparent density for brass?
No, and it is logged as a gap. Kymera publishes 3.0 to 3.7 g/cm³ and Nippon Atomized publishes 2.90 to 3.35 g/cm³ per grade. If your tooling is set to a fill density, ask for the batch figure before you order rather than after.
Sources
- 1. Kymera International, Brass (alloyed brass powder product page)Retrieved: 2026-07-30
- 2. Nippon Atomized Metal Powders Corporation, Brass powder (Product Information)Retrieved: 2026-07-30
- 3. Pometon S.p.A., Copper and copper alloyed powders, zinc and tin powdersRetrieved: 2026-07-30