For the production of our high quality products we use only the filling materials that have been specially selected by us. Continuous tests conducted in the factory laboratories provide high quality and repeatability. Regardless of the task to be performed, we have a wide range of filling materials available. Our specialists in the Sales Department will be pleased to advise you on the selection of the ideal filling material for your specific application in a particular process.

As we have mentioned, the most important element of a technical brush, apart from its construction which guarantees the adequate strength, is the type of the filling used. It is usually in direct contact with the ground / processed material and this determines its application.

Main division of the filling material:

  • wires,
  • plastics,
  • grinding fibers,
  • natural materials.


Selecting the right wire in a particular brush is very important and many physical and chemical factors should be taken into account at the same time. The purpose, working conditions and contact with the surface are significant. The quality of the wire used in brushes is extremely important because of its strength and tension. It also affects the brush abrasion and hardness. It determines the cutability of the wire brush.

The following list shows the most commonly used types of wires. Other, less popular ones are available on a special order.

Soft wire fillings type:

  • PHB - Phosphor bronze wire (CuSn), smooth or corrugated, ∅ 0.05-0.50 mm,
  • MES - Brass wire (CuZn), smooth or corrugated, ∅ 0.06-0.56 mm,

Medium-hard wire fillings type:

  • STD - Natural hardness steel wire, corrugated, ∅ 0.06-0.80 mm,
  • INOX – Stainless steel wire, acid resistant, smooth or corrugated, material standard: 1.4301/1.4310 or 1.4401/1.4571, ∅ 0.30-1.00 mm,
  • TRD - special wire, temperature resistant up to 1.350 C, corrugated, ∅ 0,30-0,50 mm

Hard wire filling type:

  • LIT - Brass steel wire, resilient, malleable, stranded, corrugated , ∅ 0.15-0.38 mm,
  • LTE - Brass steel wire, single, springy, corrugated, ∅ 0.15-0.38 mm,
  • FLA - Flat wire, hardened, smooth 1.10 x 0.25.
Physical properties of wires
1.4301 1.4310 1.4401 1.4571
Max temperature degrees Celsjus 180 220 300 450 500
Tensile strength up to N/mm2 - with the use of 0.30 mm straight wire 950 900 2000 2300 2000
Specific weight g/cm3 8,8 8,5 7,85 7,9 7,9
Type of wire TRD LIT LTE FLA
Max temperature degrees Celsjus 1350 300 300 300
Tensile strength up to N/mm2 - with the use of 0.30 mm straight wire 1800 2600 2600 2600
Specific weight g/cm3 7,9 7,85 7,85 7,85

Table – Physical properties of wires

When designing a brush with a filling material, one should remember that corrugation can reduce the strength by up to 10%.


The development of the chemical industry has led to a great diversity in the application possibilities of plastic fibers. They very often successfully replace natural fibers because of their ease of production and constant access.

Below are the most common plastics used in technical brushes:

  • PP - polypropylene, acid resistant fiber, smooth or corrugated, in diameters ranging from 0.08-1.00 mm. Possibility of color selection.
  • PA - polyamide, smooth or corrugated fiber, colors upon request. Polyamide fibers are the most popular and have their own additional classification.
    • PA 6      ⌀ 0,08 - 2,00 mm
    • PA 6.6   ⌀ 0,08 - 2,00 mm
    • PA 6.12 ⌀ 0,08 - 2,00 mm

All polyamide fiber grades are characterized by high elasticity.

  • HCB - special fiber resistant to high temperatures (max. 240 C) and extremely resistant to chemicals, smooth, ⌀ 0,20-0,60 mm. HCB is non-flammable, very stiff and resilient, flexible and resistant to abrasion. Specific weight 1.32 g/cm3.
  • PE - polyethylene, smooth fiber, in "X" profile, cut or not, colors on request, ⌀ 0.80-1.00 mm.
Physical properties of plastic fibres
PA 6 PA 6.6 PA 6.12
specific weight g/cm3 1,15 1,14 1,07
absorbability % 9,5 8,5 3
abrasion resistance in relation to PA 6.12 75 85 100
wet heat resistance 100 120 110
dry heat resistance 90 100 100
low temperatures resistance -40 -45 -40
specific weight g/cm3 0,88 0,95 1,3
absorbability % 0,1 0,1 0,3
abrasion resistance in relation to PA 6.12 60 20 80
Wet heat resistance 80 70 100
dry heat resistance 90 65 60
low temperatures resistance -10 -50 -40

Please treat the above information as an estimate - data has been collected from the external market and has been averaged. Depending on the storage and production time, data may be distorted. The chemical resistance of plastics varies. Data made available during engineering. In the range of plastics you can also find special fibers based on polyamide, electrically conductive. They are used for special purposes.

  • Abrasive fibres
    Abrasive fibers are one of the fundamental fillers today, which have changed and standardized strongly in recent times. There are only a few companies in the world that produce this abrasive.

Photo showing high magnification construction of abrasive filling, based on polyamide.

Many manufacturers use such materials, the difference is of course the quality of the fibers, which usually has a direct impact on the final price of the brush.

The soUNIQ Company in its standard solutions relies on the high quality of the products, focusing on every detail. This is no different when it comes to the selection of the abrasive fibres. We place very high demands on technical materials with regard to quality, durability, service life and ecological properties. That is why we use top quality materials with improved properties in the future brush technology.

By using the right class of materials (we offer a wide range of the filling materials), we guarantee higher efficiency at a lower cost.

Our abrasive fibres have a high heat resistance (up to 200°C).


The wide range of dimensions allows the combinations of hardness, grain size and fiber thickness (0.12 to 2.0 mm).

Extremely fine fibres (e.g. 0.6 mm diameter) are available with grain 60 (coarse-grained ). In this case, the grain sticks to the surface of the fiber, making the brush flexible, yet aggressive.

The fibers are available in both flat and round forms to meet specific requirements.

Advantages of flat filaments include: very large amount of abrasive grit, increased contact area for greater durability, 50% shorter working / deburring time, reduced contact times, 30% reduction of the brush speed reduces machine maintenance costs, uniform finish - ideal filling material for honing brushing methods,

Advantages of round fibers include: large amount of abrasive grit, the possibility of combining different wire diameters with one grain size, greater flexibility compared to flat fibers, longer service life, more suitable for combining with additional brushes. The abrasive fibers used by soUNIQ company are very efficient for smaller diameters (below 150 mm) where flat materials should not be used. It can also be used with die-cut brushes. Round fibres are better suited for soft wood structuring. Due to the higher filling density of the particular brushes, it is more suitable for workpieces with very sharp contours.


  • nylon fibers impregnated with silicon carbide,
  • uniform abrasive action provided by the design of the embedded grain,
  • high resilience and elasticity without the risk of fracture,
  • residues do not clog the filling material,
  • low absorption rate makes the product suitable for both wet and dry applications
  • resistance to weak acids and alkaline solutions,
  • long brush service life ensured by: proper rotation (22m/s tip rotation speed; low pressure; low heat development).
Standard abrasive fibre soUNIQ abrasive fibre Special fiber with conductive properties with increased temperature resistance Fibre
Temperature deformation 140˚C 160˚C Około 200˚C
Steady work 80-100˚C 100-120˚C 180˚C 250˚C
Moisture absorption 3% 3% <1%
Available Ø mm 0,45 – 1,5 0,2 – 1,5 0,4 – 0,6
Durability 100% 100% 100% 52%
Specific weight g/cm3 1,80 1,80 1,32

Comparison of physical properties

All available abrasive grit sizes (bold numbers indicate the most commonly used abrasive fibers)

3000 – 2000 – 1500 – 1200 – 1000 – 800 – 600 – 500400 – 320 – 240180 – 150 – 120 – 100 – 8060

  • Natural fibers
    Natural fillings in technical brushes have been known for a very long time and are still irreplaceable in many technological processes. They find their application wherever the lack of static properties is expected, often found when rubbing plastics. They are very popular in industries that deal with, e.g, wood processing, in pharmaceutical plants, as well as in the textile industry.


Horse hair - specially selected bristles. Antistatic. Most often in black or brown color.

Goat hair - very soft, one of the most delicate. Light, creamy color.

Chinese Pig bristles - specific and specially prepared hair, stiff. Most often black, grey or mixed with light. Can be used in temperatures above 100 degrees Celsius, in dry and wet conditions.

Tampiko, fiber from Mexican agave - one of the most popular natural fillings. It can be found in the tobacco, furniture, processing and woodworking industries. Ideal for sweeping hard to reach areas. Antistatic. Uneven due to the variety of grasses from which the fiber is prepared and properly treated. This fibre has the ability of working in temperatures up to 300 degrees Celsius in dry conditions. Characteristic yellow color, sometimes even shades of orange are possible.

Sisal lines - also all-natural product. On the market you can find mostly long and very light fibers. These are fibres of the African sisal agave.


There are situations when less common fibers used in a wide range of products need to be used. E.g, to remove static charge from a surface before painting, a filling made from specially treated peacock feathers can be used. You can also find fillings made from camel - extremely delicate, as well as fillings from coconut fibres.