Fill Material

The type of fill material used in industrial brushing tools as manufactured by Newark Brush covers a wide range to accommodate all types of brush requirements. In designating fill materials for brushes, certain code letters are used. The code letters used for the four basic types of fill material, wire, fiber, plastic and hair, are shown in the tables below. Beneath each table, the physical characteristics of some of the more commonly used materials are listed.


No CodeUntempered SteelSSStainless Steel
KPremium Tempered SteelBBrass
HTempered SteelPBPhosphor Bronze
MHigh Carbon SteelNSNickel Silver


  • Untempered steel wire – for routine work where severe cutting is not required.
  • Tempered steel – good cutting edges.
  • Special analysis high carbon – hard, good fatigue resistance.
  • Stainless steel – for brushing stainless or aluminum.¬†Good non-corrosive propertles.
  • Phosphor bronze – non-sparking; for use in explosive atmospheres.
  • Brass – non-corrosive, soft.



TNTynex NylonLLon Nylon
HNHerex NylonDDurastran


  • Tynex nylon – has highest degree of wear resistance, bend recovery, not very abrasive.
  • Polypropylene – durable, resistant to moisture, more abrasive than nylon.
  • Polystyrene – abrasive but brittle and not too durable; inexpensive.


Natural Fiber

WTDWhite Tampico (dry)BHBahia
WTT White Tampico (Regular Treatment)BSBassine
GTGrey TampicoPMPalmyra


  • Soft hairs – ox, squirrel, or goat hair.
  • Harsh hairs – stiff horsehair or hog bristle.


Fill Density

Fill density can be varied considerably. Two brushes of approximately the same diameter, face, and trim length may have a 100-percent difference in fill weight. Densely filled brushes are used where fast-cutting, uniform surface effects or finer surface finishes are required. An “open” structure is used when a whipping or flicking action is desired from the wire. This is obtained by using more deeply crimped wire. A fine crimped wire packs more and gives a more dense brush.


A short trim gives a hard, stiff brush that is fast cutting and rugged. A short trim provides better control of the brushing surface required for finer, more uniform finishes. Longer trim lengths are used to provide flexibility required when brushing irregular surfaces.


The horsepower required will depend on the surface speed at which the brush operates, the pressure the operator uses in applying the brush to the work, the area of the brush in contact with the work, and the coefficient of friction. General recommendations are shown below as indications of the probable power requirement for 1-inch brush faces.



Brush Speed

The best speed at which a brush operates must be determined by the requirements of the particular job. The higher the rotary speed, the firmer and harder the brush will be because of centrifugal action. It is for this reason that fine wire brushes operated at high speeds act like coarser brushes at lower speeds. If experience is gained on a job with a certain diameter brush at a given speed, changes of operating conditions can be made without adverse effect by maintaining approximately the same surface speed. Approximate surface speeds for various brush diameters and rotary speeds are shown below.

Approximate Surface Speed (Ft./Min.)

Brush Diameter

Special Designs

Newark Brush maintains a modern laboratory equipped with specialized equipment designed to allow evaluations of all types of brushing applications. We have tried to give you a guide to brush selection in the tables above. But we also welcome your inquiries and sample workpieces that can be studied at no cost to you by our Newark Brush Consultants.