Brushes Technical Information

The selection of the right type of brush depends on the type of finishing required (fine or coarse), and the characteristics of the surface to be brushed (stainless steel, carbon steel, wood, etc…).

Besides that, in the case of the brushes fixed in a machine, it is necesary to know the main features of the machine in order to choose the right brush type:

  • The maximum diameter allowed
  • The machine speed or RPM.
  • The arbor hole diameter or the thread type (M14, 5/8"- 11, etc...).
 

Trim Length

A short trim length makes the brush face rigid and consequently the brush removal capacity is higher.

With a longer trim length the brush becomes flexible and it provides a uniform brushing even on irregular surfaces.

 

Crimped wire, Twisted Knot Wire and Nylon

Crimped wire brushes, because of their higher flexibility, are appropiate to work on uneven surfaces and they obtain a more regular and fine finishing.

Twist knot wire, offers longer life and a higher removal capacity but a more rough finishing.

Nylon brushes have the flexibility of crimped wire and offers a smoother finishing.

 

Wire Brushes Vs. Hard Abrasives

Wire brushes act as an impact tool removing oxide, paint or other adherence from the surface without damaging the base material, as opposed to hard abrasives which will remove the base material along with the surface adherence. Wire brushes are much more flexible allowing the ability to clean difficult areas to reach and adapt to irregular surfaces, which bonded and coated abrasives can not.

 

Safety Warnings

The European Standard EN 1083-2 about Safety Requirements in the use of Power-driven brushes states the safety instructions that all brush operators must observe. These requirements and common safety practices will reduce the likelihood of physical injury and brush fail:

  • Wear safety goggles, protective clothing and equipment.
  • Observe all speed restrictions indicated on the brushes, packaging or catalogue. And do not exceed Maximum Safe Free Speed (Max. R.P.M.) under any circumstances.
  • Keep all machine guards in place.
  • Do not use deteriorated brushes.
  • Oxidation or any other chemical alteration in the wire may cause malfunctioning.
  • Store brushes in original packaging, in a clean and dry location protected from dust, humidity and other environmental effects.
 

Brush Usage Recommendations

The brushing must be performed with wire ends. Excessive pressure causes over-bending of the wires, increasing their fatigue and therefore, causing a premature breaking, reducing significantly their working life.

If you need a higher removal capacity, instead of higher pressure on the brush, we suggest the following:

  • Use a more aggresive brush: A brush with a thicker wire, with less trim lenght or twist knot wire instead crimped wire.
  • Increase the brushing speed with a model who can work faster or with a bigger diameter, in the case of the wheel brushes.

Wire Diameter and Characteristics of Nylon

Wire gauge of a brush determines the type of surface finishing:

  • A thicker wire provides for a more aggressive brushing action.
  • The larger the nylon grit size is the smoother finishing you get.
  • Cuanto mayor es el número del grano de nylon, el acabado es más fino.
Machine
(Normal Speed)
Most common brushesModelBrush diameter
Bench Grinders Crimped & Knotted Wheels CT, CU, CAM,
CCA, DNA, CTP
75 mm (3") TO 350 mm (14")
Angle Grinders (5.000 - 8.500 RPM) Crimped & Knotted Wheels CT, CAM, CPL,
CCA, CTP
100 mm (4") TO 175 mm (7")
Crimped & Knotted Cups TO, TT, TCA,TOG,
TTG, TCAG, TNA, TOT, TTP
80 mm (3.1/4") TO 150 mm (6")
Flap Discs DLZ, DLO.  
Mini Angle Grinders (10.000 - 12.500 RPM) High Speed Cups, Discs & Wheels HSC, HST, HSD, HSK, HSP, HSR, HCA, HSCG, HSTG, HCAG, HSKG, HSDG, HSCP, HSTP, HSRP 65 mm (2.9/16") TO 115 mm (4.1/2")
Flap Discs DLZ, DLO.  
Drill & Pneumatic Tools (15.000 - 20.000 RPM) Wheels & End Brushes with Shank CDE, CAE, B. 12 mm (1/2") TO 75 mm (3")
Flap Wheels AL.  
Drills (4.500 RPM) Wheels, Cups & End Brushes with Shank BDER, BTE, BBC,
BDOR, CNA.
26 mm (1") TO 100 mm (4")
Flap Wheels AL.  

 

New Colours

From now on, to help our customers to identify the different types of wire of our brushes, we show in the plates the colour range already used on the labels.

 

RPM

The power tool speed influences the performance of the brush and the safety of the operador. If load speed marked on the power tool is higher than the brush MAXIMUM RPM, do not mount the brush. Maximum RPM are indicated on brush side plates and shall never be exceeded. MAXIMUM RPM are the maximum RPM at which the brush could be run with no work applied (spinning free). It is merely a safety indication for the user, not the recommended operating speed.

Peripherical Speed [m/s]

RemovalSteelStainless steel and brassNylon
Burr 25-35m/s 20-25m/s 15-20m/s
Weld pass 40-45m/s 35-35m/s  
Oxides, varnishes, corrosion 30-35m/s 20-25m/s 15-20m/s
Paints and scales 40-45m/s 35-35m/s  

Converting m/sec in ft/min:

1 m/sec = 197 ft/min

1ft/min = 5,08 m/sec

 

nBrush Ø d1 [mm]
[r.p.m.]25304050607580100115125150175200250300
1.000 1 2 2 3 3 4 4 5 6 7 8 9 10 13 16
1.250 2 2 3 3 4 5 5 7 8 8 10 11 13 16 20
1.500 2 2 3 4 5 6 6 8 9 10 12 14 16 20 24
1.750 2 3 4 5 5 7 7 9 11 11 14 16 18 23 27
2.000 3 3 4 5 6 8 8 10 12 13 16 18 21 26 31
2.500 3 4 5 7 8 10 10 13 15 16 20 23 26 33 39
3.000 4 5 6 8 9 12 13 16 18 20 24 27 31 39 47
3.500 5 5 7 9 11 14 15 18 21 23 27 32 37 46 55
4.000 5 6 8 10 13 16 17 21 24 26 31 37 42 52 63
4.500 6 7 9 12 14 18 19 24 27 29 35 41 47 59 71
5.000 7 8 10 13 16 20 21 26 30 33 39 46 52 65 79
5.500 7 9 12 14 17 22 23 29 33 36 43 50 58 72  
6.000 8 9 13 16 19 24 25 31 36 39 47 55 63 79  
6.500 9 10 14 17 20 26 27 34 39 43 51 60 68    
7.000 9 11 15 18 22 27 29 37 42 46 55 64 73    
7.500 10 12 16 20 24 29 31 39 45 49 59 69 79    
8.000 10 13 17 21 25 31 34 42 48 52 63 73      
10.000 13 16 21 26 31 39 42 52 60 65 79        
12.000 16 19 25 31 38 47 50 63 72 79          
14.000 18 22 29 37 44 55 59 73              
16.000 21 25 34 42 50 63 67                
20.000 26 31 42 52 63 79                  
22.000 29 35 46 58 69                    
25.000 33 39 52 65 79                    

Example
Brush diameter d1=150mm
RPM: 3000 r.p.m
Cutting Speed: 24m/s

RPM: 5.000 r.p.m.

Cutting speed (v) =
d1 x p x nº de rev. (n)
1.000 x 60