Glossary Definition


Brush Types

Wheel Brushes

The circumferential edge or “face” of this circular style brush performs the work.  Wheel brushes are ideal for removal of material, flash, rust, paint, cleaning weld bead, deburring, deflashing, edge blending, skiving and buffing. Osborn standard wheel brushes are produced in a full range of diameters, with a selection of operating face widths to perform almost any finishing task. Fill materials include both crimped and straight wires of steel and stainless steel, brass and other nonferrous metals; treated and untreated natural fibers; and synthetics such as nylon, plastic, and ATB filaments for dry and wet abrasive action. Brush diameters range from 5/8” to 22”.

Cup Brushes

Osborn cup style brushes are made in three types: knotted wire in steel and stainless steel for heavy duty, crimped wire for lighter surface preparation and deburring service, and ATB filaments for finishing work. Cup brushes are easily mounted on CNC machines and portable tools, air-or electric-powered. Standard brush part diameters range from less than one inch up to nine inches, with wire diameters from .006” to .035”.

End Brushes

As the name indicates, this style is designed to have the ends of the fill strands do the bulk of the work, although the sides can also be used to finish vertical surfaces that parallel the shaft. Especially suitable for CNC machines, portable air and electric tools in tight spaces, end brushes are made in knot, crimped, and straight wire of carbon and stainless steel, brass, ATB filaments and other non-metallics, with brush diameters ranging from 3/16” to 3”.

Internal Finishing Brushes

Also known as a “side action” brush, this style is primarily used in CNC machines, portable tools and drill presses for cross hole deburring and fast cleaning and finishing of such inaccessible surfaces as small diameter bores and internally threaded surfaces. Osborn internal finishing brushes are made in steel, stainless steel, brass, nylon and ATB filaments. A number of special purpose power and manual styles are included in the internal finishing category: tube, tube & flue, frill, and Sibot ™ brushes. Sizes range from .030” up to 10”.

Wide Face Brushes

Wide Face brushes are designed for surface conditioning, finishing, scrubbing and cleaning of metal coil and sheet stock, shaped products, and such specialties as printed circuit boards. The brushes are also used on annealing/ pickling, galvanizing, paint coating, and other large area, high production lines. They prevent costly build-up and wear on conveyor belts in a variety of manufacturing and processing environments. Outside diameters range from a few inches to over one foot. Standard face widths span from two inches to nearly twenty feet and, with the ability to combine multiple brushes at your site, total width is easily customized to any application.

Filament Types

Carbon Steel Wire

Either crimped or straight, this proprietary, special analysis steel wire was developed exclusively for Osborn, and features extremely high resistance to fatigue, with outstanding cutting ability on edges, burrs, etc.

Stainless Steel Wire

All Osborn stainless steel wire, straight or crimped, is Type 302, highly resistant to corrosion and high temperatures. Used in brushing stainless steel, aluminum, and other exotic metals. Particularly suited for nuclear work, naval, aircraft, and aerospace construction.

TY Elastomeric Encapsulation

Metal wire is firmly bonded within tough TY elastomeric materials, supporting each individual tip at the work surface. In use, the elastomer wears back gradually, thereby presenting a constant short wire trim for maximum cut and safer use.

Green TY Encapsulated models are for standard duty and use a pliant elastomer for a semi-flexible brushing face.

Yellow TY Encapsulated models are for heavy duty and use a harder elastomer, producing a rigid brushing face.

Black Max TY Encapsulated models are for extra heavy duty and use a very hard black elastomer which is excellent for cleaning stringer beads and other narrow-area cleaning.

Non-Ferrous Wire

Several types of brushes filled with brass wire are stock items, with brass and other non-ferrous fill available on special order for most brushes.

Non-Metallic Natural Fibers

Untreated tampico works well on wet or dry surfaces. Treated Tampico natural fiber brushes, used with abrasive compounds are excellent for removal of burrs and tool marks and for blending surface junctures.

Advanced Technology Brushing ATB™ Filaments

Osborn's ATB brush tools are made with heat stabilized nylon filaments impregnated with Silicon Carbide, Aluminum Oxide or Polycrystalline Diamond grit. Grit loading ranges from 10-40% by weight, offering a wide variety of filament choices. ATB filaments work like independent flexible files conforming to part contours and abrading edges & surfaces. ATB abrasive tools produce fast, consistent, repeatable results, lowering process costs and creating a cleaner more efficient working environment.

Non-Metallic Synthetic Fibers

Osborn synthetic fills include nylon, plastic coated fiberglass and crimped monofilament. The synthetic fills can be used in wet or dry applications, with or without compounds.

Power Brush Terminology

Outside Diameter

The outside diameter, or O.D., is the basic overall size of the brush as measured through the center from two opposite points on the circumference.  A larger brush diameter results in a more efficient finishing tool.  Production economies are obtained through lower end-of-service costs.  Wire brushes 12" O.D. are a practical size, wher 12" to 16" O.D is usually best for non-metallic types.  Sizes for portable tools (6,000 RPM maximum) should not exceed 6" O.D. in any materials.

Inside Diameter

The inside diameter, or I.D., is the diameter of the brush back measured across the center from two opposite points on the flange or plate. (I.D. should not be confused with the arbor hole which defines the central opening by which the brush is attached to the tool or machine.)  Increasing the inside diameter of a brush while maintaining the outside diameter results in a stiffer, less flexible face since it effectively reduces the trim length.

Trim Length  

This term refers to the length of the fill material that extends beyond the brush back or face plates.  A short trim makes a stiff, fast-cutting brush, while a long trim gives a brush added flexibility that better enables it to contact irregular surfaces.

Face Width

This is the width of the working surface of a wheel brush, comparable to the tread area of a tire.  All the face widths shown in this catalog are computed while brushes are in operations.

Fill Density

Density is the number of wires or filaments in the brushing surface.  High density brushes produce finer surface finishes and are also used where fast cutting is required, as in deburring.  Low density brushes offer greater flexibility, providing efficient removal of rust, scale, and other encrustations through the whip-like action of the wires on the surface.


Flexibility is that quality of a brush which determines its resiliency and ability to reach into confined areas and conform to uneven or contoured surfaces.  It is determined by the overall interaction of inner and outer diameters, trim length, fill density, fill material, and RPM. (Not illustrated here.)

Brushing Speed and Pressure

The RPM speeds shown for Osborn power brushes are Maximum Safe Free Speeds (MSFS).  In most operations, a lower speed than the MSFS will prove more efficient for you.  Lower speeds and lighter pressures give longer brush life, generate less heat in the work, and require less power.

With wire brushes, the tips of the filaments do the actual work.  With ATB brushes, the tips and sides of the filaments do the work.

Where high brush pressures and speeds are required, it is recommended that a more aggressive brush be used.  This may be done by increasing wire size and/or abrasive grit size, decreasing trim length, or in some instances, changing to another brush type.

Steel Wire Quality

Osborn Steel Wire is a proprietary product developed by Osborn and used exclusively for OSborn power brushes.  It has outstanding cutting acton and excellent fatigue resistance for long, efficient brush life.

Straight Wire - is used in knot-type brushes and provides maximum impact action for weld cleaning, heavy burr removal, and all jobs requiring fast, severe cutting performance.

Crimped Wire - is used in Osborn conventional brushes of all types: wheel, cup, end, and internal action.  It provides controlled tip action (continuous brushing action) and is excellent for producing fine finishes and removing light burrs.

Knot Types

Standard Twist Knot - is good for cleaning groove, t-connections and welded beads, and for general surface prepration.  It is used in all types of wire brushes.

Cable Twist Knot - is excellent for standard knot wire applications that need more aggressive action and is most commonly used in wheel brushes.

Stringer Bead Knot - is excellent for bead scale removal.