MaterialSynthetic Filaments
PA612 Nylon
Long-chain polyamide filament
PA612 is the nylon for wet work. A long-chain polyamide, it takes up a fraction of the water that PA6 and PA66 do, so it keeps its stiffness and bend recovery in water and holds a stable trim. It costs more, so it earns its place where a brush is wet for long periods or has to keep precise geometry.
What is PA612, and how is it different from PA6?
PA612, or nylon 6.12, has longer carbon chains between its amide groups than PA6 or PA66. The amide groups are what attract water, so with fewer of them per length, PA612 absorbs much less: about 1.2–1.3% at 50% relative humidity and about 3% at saturation, against 8–10% for PA6. It keeps around 70–75% of its dry stiffness when wet.
It is medium to firm, about Shore D 70–80, with a density of 1.06–1.07 g/cm³ and a melting point of 212–218°C. Brush filament runs from about 0.075 mm to 2.5 mm.
Where is PA612 used?
In our range, in about thirty brushes where wet stability or recovery matters: medical cannula and instrument brushes, nylon tube brushes and cooling tower brushes, plating line rollers, solar panel brushes and strips, floor burnisher brushes, grout and slot brushes, printer brushes and brush wheels. The common thread is that the brush either works wet or has to keep its exact size and stiffness over many cycles.
How hot can a PA612 brush run?
The published limits for PA612 brush filament are about 93°C continuous and 121°C short-term, the same as PA6. Its advantage is not heat but water. For hot dry work, PA66 has more margin; for hot wet work, PBT.
Which chemicals suit PA612?
Like other nylons, it resists water, oils, fuels, most solvents, detergents and dilute alkalis, and is attacked by strong mineral acids, phenols and strong oxidizers. Its low water uptake also keeps its size and stiffness steadier than PA6 through repeated wash and dry cycles, which suits reusable medical brushes.
When is PA612 worth the extra cost?
- When the brush is wet for hours and must not go limp: tube, tank and line brushes.
- When trim geometry must stay stable, as in precision tube and roller brushes.
- When the brush is washed and reused many times, as in medical and lab brushes.
For dry or occasionally wet cleaning, PA6 or PA66 do the job for less. For brushes that sit in acid, PP or PBT are better.
What should you tell us when you ask for a PA612 brush?
- How long the brush is wet, and the water or cleaner temperature.
- Reprocessing or washing cycles, if the brush is reused.
- Filament diameter and trim, or a sample to match.
- Material documentation needed, and the quantity per design.
Questions buyers ask about PA612 Nylon
Why choose PA612 instead of ordinary nylon?
Because it takes up far less water, about 3% at saturation against 8–10% for PA6, so it keeps most of its stiffness and recovery when wet. Choose it for brushes that work wet for long periods or must keep precise size and stiffness.
Is PA612 more heat-resistant than PA66?
No. Its published limits are about 93°C continuous and 121°C short-term, below PA66's 120°C continuous in dry heat. PA612's advantage is wet stability, not heat.
Why is PA612 used in medical cleaning brushes?
Reusable medical brushes are washed and dried again and again. PA612 takes up little water, so it keeps its stiffness and size through those cycles better than PA6. The instrument maker's instructions still decide which brush is used.
Where these figures come from
| Property | Published value | Source |
|---|---|---|
| Chemical resistance | Good resistance to water, oils, mild detergents and dilute alkalis; strong mineral acids, phenols and strong oxidizers attack the polymer; for long-life wet cleaning, precision tube brushing and premium roller or strip brushes where stable trim geometry matters, specify the carrier grade, cleaner co | Perlon Retrieved 2026-07-20 |
| Hardness and stiffness | Medium to firm; Shore D about 70-80; premium filament with strong bend recovery and dimensional stability. | Perlon Retrieved 2026-07-20 |
| Limitations | PA612 costs more than general PA6 and should be used where its wet stability, recovery or wear life creates a real process benefit. | Perlon Retrieved 2026-07-20 |
| Material definition | PA612 is a long-chain polyamide with lower water absorption than PA6 or PA66 and resistance to many oils, fuels, cleaners and saline solutions. | Perlon Retrieved 2026-07-20 |
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Discuss This Material
Share what the brush works on, the temperature and chemicals it meets, the form you need — strip, disc, roller or hand brush — the quantity and a drawing or photo.
We reply to every request within 24 hours, with a quotation or with the questions we need answered first. If the brush can be made on our existing tooling, we make the sample directly. If it needs new tooling, we quote a sample fee and a tooling fee, and the sample fee is credited against the bulk order. Need an NDA first? We sign yours before you send drawings, and the files you send are never shown to other customers.
- MOQ500 pcs for small hand-held brushes, 100 pcs for medium and large ones
- SampleTypically 3–7 days
- ProductionFrom 7 days after sample approval, by size and quantity
- Payment30% deposit and 70% before shipment above US$10,000; smaller orders on agreed terms
“We need a brush to remove wet residue from a stainless steel conveyor, about 800mm wide. The current brush wears quickly. We can send photos.”
“We sell drinkware and need a cleaning brush to include with the product. Quantity around 5,000 pieces.”