Bronze PTFE filler powders
Bronze fillers for PTFE compounds
Overview
Bronze powders used as fillers in PTFE compounds for bearings, bushings and seals, improving wear resistance, thermal conductivity and load capacity over unfilled PTFE. A fine size range from -100 mesh (150 µm) down to -500 mesh (25 µm) suits compounding and even dispersion.
Bronze fillers that turn PTFE into a bearing material: wear resistance, thermal conductivity and load capacity that unfilled PTFE cannot reach.
Capabilities
- Bronze powders used as fillers in PTFE compounds for bearings, bushings and seals
- Improve wear resistance over unfilled PTFE
- Improve thermal conductivity and load capacity
- Four grades from -100# (150 µm) to -500# (25 µm)
- Fine sizing suits compounding and even dispersion
- Composition-controlled grades including a CSPZ 45 fine cut
Specifications
| Type | Bronze PTFE filler powders |
| Size range | Available under controlled technical briefing |
| Particle shape | Irregular |
| Duty | PTFE bearings, bushings, seals |
| Quality system | Available under controlled technical briefing |
| Origin | Independent / non-aligned |
Why Unstrat: the difference
Unstrat is the authorised global representative and distributor for this capability. It is already in service with a track record behind it, so you are buying something that has done the job elsewhere, not funding a first attempt. You are not the test bed.
Independent, non-aligned origin, with no political exposure to any major-power ecosystem.
One accountable team from first briefing through delivery and in-region sustainment.
Size range from -100 mesh down to -500 mesh (25 µm) for even dispersion in compounding.
How it reaches you
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Procurement & sustainment
Classification and the end-user-certificate chain are confirmed before this capability is represented to your market.
Sourced from an independent manufacturer: no major-power disclosure rules or political conditions.
A single team responsible from first briefing through delivery: not a chain of foreign primes to integrate yourself.
Lifecycle support and operator training delivered in-region, building capability that outlasts the initial deployment.
Questions buyers ask
Bronze filler for PTFE bearings and seals
Bronze-filled PTFE gains wear resistance, thermal conductivity and load capacity that unfilled PTFE cannot reach, which is why it dominates hydraulic seal and bushing work. Our filler grades run from -100 mesh at 150 µm down to -500 mesh at 25 µm, composition-controlled across the range, and they are in production use in PTFE bearings, bushings and seals under an ISO 9001:2015 system.
See: Filler grades and size rangeCompared with Makin and Pometon
Finest bronze powder available for compounding
Our finest published cut is -500# at 25 µm, on the CSPZ 45 grade, and it is a composition-controlled bronze rather than an ultra-fine copper. Makin's finest published zinc bronze is -350#, with its ultra-fine offering at d(0.50) of 5, 10 and 20 microns published under copper rather than as an alloyed filler bronze. In a seal compound that distinction decides what actually disperses.
PTFE filler powder supplier
Four grades cover the compounding range, from -100# through -200# and -325# to -500#, with the main grades at Zn 1.75 to 2.85%, Sn 8.5 to 9.5% and copper balance, and the CSPZ 45 fine grade at a distinct chemistry. Makin and Pometon both publish bronze for PTFE compounding too, so this is a genuine like-for-like choice rather than a niche.
Why does filler particle size matter so much in a PTFE seal?
A bronze-filled PTFE seal fails at the agglomerate, not at the average particle. Coarse filler in a thin-wall bushing produces a wear surface with weak points, which is precisely why the fine cuts exist. The useful question at enquiry is what the finest reliable cut is and whether it is an alloyed bronze or a copper powder, because those behave differently in a compound.
Bronze filler grades that hold one chemistry across several cuts
That is how the main range is built: one composition family across a fourfold size span, so a compounder can change cut without requalifying the chemistry. It matters when a seal grade moves from a coarse hydraulic application to a thin-wall bushing. CSPZ 45 is the deliberate exception, published as a distinct chemistry for the finest work rather than presented as the same material sieved harder.
See: Composition control across four cutsFiller powder detail
Do you publish apparent density for the PTFE filler grades?
No. Makin publishes 2.5 to 4.0 g/cc for irregular zinc bronze and 1.0 to 3.0 g/cc for dendritic. Ours is measured per batch and issued on request, and the missing published figure is logged as a gap rather than dressed up. If your compounding line is set to a bulk density, ask for the batch measurement before you order.
See: Apparent density row
Do you offer dendritic bronze filler?
No, our published morphology is irregular only. Makin publishes a dendritic option for the same duty, and dendritic particles interlock differently in a compound, which some seal formulators want specifically. If mechanical keying is central to your formulation, that is a real reason to buy from them, and it is worth settling before a compounding trial rather than after.
See: Morphology row
Filler bronze supplier outside European supply chains
Seal and bushing production is unglamorous and easy to interrupt, which is what makes it worth checking. Makin is a UK producer and Pometon an Italian one, both stated in their own material. Our filler grades come from an independent, non-aligned producer in current production supply for PTFE bearings, bushings and seals. Makin publishes more process data; we publish a finer alloyed cut and a different jurisdiction.
Bronze filler grade for thin-wall PTFE bushings
Wall thickness is what should decide the cut. Coarse filler in a thin wall leaves a wear surface with weak points, so the -325# and -500# grades exist for that work, with CSPZ 45 at 25 µm as the finest published option. The coarser -100# and -200# grades suit heavier hydraulic sections where dispersion is less marginal.
How much difference does bronze filler actually make to PTFE bearing performance?
Filled PTFE gains wear resistance, thermal conductivity and load capacity that unfilled PTFE cannot reach, which is why bronze-filled compounds dominate hydraulic seal and bushing work. The size distribution then sets how evenly that improvement is spread through the part. A coarse filler gives you the same average composition with a worse worst case, and the worst case is what fails.
We compound hydraulic seals for a licensed programme meant to reduce foreign dependency. Does the filler source undermine that?
It can, quietly. If the seals are made locally but the filler bronze arrives from inside another bloc's export regime, the dependency has simply moved one layer down the bill of materials, where nobody audits it. The material class is the same wherever you buy it; the exposure is not. Our filler grades are in production supply from an independent producer, so the layer below the licence is covered too.
What should we test on incoming filler bronze that the datasheet does not cover?
Bulk or apparent density, because it is not on our published sheet and it drifts before anything else does. Add a dispersion check on a small compound sample rather than trusting the sieve alone, since agglomerates pass a mesh test and then ruin a seal. Oxygen is not published for our filler grades either, so if your process is oxygen-sensitive, make it a contractual acceptance value.
See: Gaps we log openly
Is the CSPZ 45 grade just the standard bronze sieved finer?
No, and we publish it as a separate chemistry for that reason. The main grades run Zn 1.75 to 2.85% and Sn 8.5 to 9.5% with copper balance; CSPZ 45 sits at Sn 6 to 8%, Pb 2.5 to 3.5% and Zn 6 to 8% with copper balance. Treating it as the same material at a smaller cut would mislead a formulator about how it behaves, so it is listed as what it is.
See: Composition rows
Can one supplier cover both the filler bronze and the pressed bronze in the same plant?
Yes, and it usually simplifies the qualification. The pressed bronze range runs seven compositions from 90/10 to 62/38 at -325 mesh, and the filler line covers -100# to -500#, both from the same house under one ISO 9001:2015 system. That means one incoming test regime and one supplier accountable for variance, instead of a bearing line and a compounding line each managing their own.
How do we decide between Makin's published data and a finer alloyed cut?
Ask which risk is live for you. If the formulation is settled and you need to match a documented bulk density and morphology, Makin publishes across four apparent density bands with a dendritic option, and that shortens your work. If dispersion at the fine end is the failure you keep chasing, an alloyed bronze at 25 µm addresses it directly. Both are defensible; picking on marketing rather than the failure mode is not.
Bronze PTFE filler powders: questions
What are Bronze PTFE filler powders?
Bronze PTFE filler powders are Unstrat's Land (Land Domain) capability: Bronze powders used as fillers in PTFE compounds for bearings, bushings and seals, improving wear resistance, thermal conductivity and load capacity over unfilled PTFE. A fine size range from -100 mesh (150 µm) down to -500 mesh (25 µm) suits compounding and even dispersion.
How do Bronze PTFE filler powders work?
Bronze PTFE filler powders deliver their effect through bronze powders used as fillers in PTFE compounds for bearings, bushings and seals, Improve wear resistance over unfilled PTFE and Improve thermal conductivity and load capacity, capabilities matched to the requirement and confirmed under briefing rather than published.
Who makes Bronze PTFE filler powders?
Bronze PTFE filler powders are built by The Specialty Alloys Producer, whose focus is tungsten heavy alloys & specialty metal powders. Unstrat represents The Specialty Alloys Producer to government and enterprise buyers worldwide as an independent, non-aligned prime vendor.
Why choose Bronze PTFE filler powders over a major-power alternative?
Bronze PTFE filler powders are sourced from an independent, non-aligned manufacturer, so they carry no major-power disclosure rules, upgrade-locks or political ramifications. Concretely: size range from -100 mesh down to -500 mesh (25 µm) for even dispersion in compounding. The capability is accountable to you, not to a foreign vendor's government and its release schedule.
How are Bronze PTFE filler powders procured, and where can it be exported?
Bronze fillers that turn PTFE into a bearing material: wear resistance, thermal conductivity and load capacity that unfilled PTFE cannot reach. Every engagement begins with a briefing, and export eligibility is confirmed per market under briefing rather than published. Where controlled capabilities are involved, the classification and end-user-certificate chain is confirmed first. Bronze PTFE filler powders are then sustained in-region by one accountable team from briefing through long-term operation.