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grinding wheel factory
Basic information on grinding wheels classes of grinding Rough grinding and cutting Precise grinding Hand grinding Diamond and cubid boron nitride grinding tools
autorizovaný importér a distribútor

Hradná 6/188
945 01 Komárno
SLOVAKIA

tel.:
+421 35 7900020
fax:
+421 35 7900029
email:
info@swaty.sk
Quality specification
Products >Diamond and cubid boron nitride grinding tools > DIAMOND AND CBN GRINDING TOOLS "DIABON" IN RESINOID BOND

Quality specification

When choosing grain size you have to consider that fine grain sizes give better surface finish and increase profile persistence but dicrease grinding effectivness.

Therefore it is most economical to choose the coarsest grain size that still gives requierd surface quality. Diamond and CBN grain sizes according to FEPA standard are shown in the table below.

Table of grain sizes
601 Coarse
501
426
356
301
251
213
181
151
126
107
91
76
64
54
46 Fine
Type of grinding Grain size
Very rough grinding D 151-126
B 151-126
Rough grinding D 107-64
B 107-64
Fine grinding D 54-46
B 54-46
Precise grinding and polishing 0-15 mikro m
10-12 mikro m
Hardness Application
N Medium for grinding wheels and cups with wide abrasive layer
R Hard for grinding cups with standard abrasive layer quality and wheels with increased resistance to wear
T Very hard for special applications

Hardness of grainding tool depends on bond quantity and bond structure.

Bond Application
B 40S universal application (wet and dry grinding)
B 45S for wet and dry grinding, for grinding of special materials (combination of steel and tungsten carbide)
B 47S for CBN grinding tools

Concentration of diamond or CBN grain is the weight of diamond or CBN grain in one volume unit (cm3) of abrasive coating. Concentration 100 means there are 0,88 grams (4,4 carats) of diamond or CBN grain in one cm3 of abrasive coating, i.e. about 25 % of total volume. Other concentrations are shown in the table.

Concentracion % g/cm3 carats ct/cm3
25 0,22 1,1
50 0,44 2,2
75 0,66 3,3
100 0,88 4,4
125 1,10 5,5
150 1,32 6,6

Effectiveness of DIABON grinding tools depends much on the concentration of diamond or CBN grain.

High concentration (100 - 125)

is used with rougher grain sizes, for cylindrical and profile grinding, by small contact areas, and by narrower abrasive coating.

Low concentration (50-75)

is used with finer grain sizes, for frontal and flat grinding (cup wheels), and by wider abrasive coating.

Peripheral speed

depends on grinding process (grinding, sharpening), on grinding method (wet or dry grinding), and on required surface quality. Higher peripheral speeds enable better surface finish and reduce wearing out of the grinding tool. Consequently it is more economical to use medium peripheral speeds by very rough grinding and by sharpening since at such speeds it is possible to flush away grinding dust and carry off heat continuously.

The following guidelines can be of help for choosing the correct peripheral speed:

Type of grinding Grinding method
Wet Dry
Diamond CBN Diamond CBN
Surface grinding 20 - 30 m/s 22 - 35 m/s
Internal grinding 10 - 20 m/s 18 - 30 m/s 8 - 12 m/s 15 - 20 m/s
Cylindrical grinding 20 - 30 m/s 25 - 35 m/s
Tool grinding 18 - 28 m/s 20 - 30 m/s 15 - 20 m/s 18 - 25 m/s
Abrasive Application Abrasive characteristics during grinding
Wet grinding Dry grinding
description grit description material material
Synthetical diamond with metal coating 101D Carbide metal
General application
Carbide metal
General application
Good cutting ability
Good for sharpening and external round grinding
102D Carbide metal
Combination carbide metal/steel
Carbide metal
Combination carbide metal/ <15% steel
Good cutting ability
Optimum relation between cutting ability and pressure of grinding
103D Carbide metal
Ceramic carbide metal on the basis of TiC-TiN
Carbide metal
Ceramics
Very good cutting ability
Good durability
No cracks in material by grinding
104D Carbide metal
Combination carbide metal/ <15% - 75% steel
Optimum durability
Increased grinding pressure
Optimum economy considering effectivness
105D Carbide metal
Ceramics
Carbide metal
Ceramics
Microgrits (from D15 to D30)
CBN with metal coating 101B Precise grinding of steel matrices, alloyed steels, stainless steels, and other hard alloyed steels of hardness between 58-64 HRc Good cutting ability
Appropriate for sharpening
102B Good workpiece surface
Good cutting ability
Good durability of wheel
Redused grinding pressure
103B Increased toughnes
Increased thermal resistance
Maximum grinding wheel durability
Increased material removal ability
Worse workpiece surface

Mounting of grinding tools

Balancing of DIABON grinding tools is so accurate that by properly mounted tool the radial and axial stroke are not bigger than 0,02 mm. Hole tolerance is H7. By tool mountig well balanced flanges should be used. All contact areas (flange-spindle and flange-grinding tool) should be clean. On grinding tools with frontal abrasive coating rotating direction is always marked by an arrow and it must be obligatory considered when mounting the tool on the grinding machine. Diamond and CBN grinding tools should therefore be used on well maintained grinding machines with stable construction so that no vibrations appear during grinding process. If the grinding machine vibrates workpiece surface quality is not good and grinding tool wears out faster.

Maintenance

If all grinding parameters are chosen properly, grinding tool is self-sharpening.

If application is not correct, abrasive coating fills up with grinding dust and gets blunt. In such a case sharpening is needed to open the structure and remove the grinding dust.

How to open the abrasive coating

- with silicion carbide or white aluminium oxide grinding wheels in hardness I-L and in a little coarser grain size than the applied DIABON grinding tool is. Truing grinding wheel should be mounted on a supporting grinding machine and should rotate in the same direction as the DIABON grinding tool, however with a speed 20 - 30 m/s. DIABON grinding tool should rotate with small peripheral speed 12 m/s.

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