CBN and Diamond Tooling

Kemet offer a comprehensive range of Diamond and CBN wheels from standardize to customize wheel range from 3mm up to 750mm of diameter based on FEPA standard shape and/or custom design. Kemet Diamond Tools provides four types of bonding. The purpose of the bonding material is to hold the abrasive grain particles together. Each of them has different advantages and characteristics according to the material they cut.

Vitrified Bonds - Vitrified wheels have a glass bond composition. Vitrified wheels hold form extremely well and produce a high ratio of stock removal to wheel use. Such wheels are commonly used for precision grinding in the tool and die market

Electro Plated - A plated grinding wheel has a single layer of abrasive material that’s exposed to the surface, instead of embedding the material within a bonding compound.

Resin Bonds – The resins that bond abrasives to grinding wheels are typically phenolic resins, meaning that they are made by reacting phenol. The resin also contains filler materials such as copper and an abrasive material like diamond or CBN. A hot press compresses this mixture into the desired form, which is then cured and machined to a precise shape. Resin Bond is widely used in the cutting tools industry

Metal Bonds - The metal bonds used by grinding wheels are typically made by sintering powdered metals along with filler materials, and adding an abrasive such as CBN or diamond. These bonds are very strong, providing a grinding wheel that holds its shape well. The durability of metal bonds also means that these grinding wheels require dressing less frequently.

Grain size selection - General Principles, choose a coarse grit size as long as the grinding result is still acceptable. Besides the grit size the type of diamond or CBN also plays an important role in determining the results of grinding. Coarse Grit sizes for - High Removal Rate - Rough Surface on Material - Better Tool Life. Fine Grit sizes for - Lower Removal Rate - Fine Roughness on workpiece - Shorter Tool Life Different

All our products are made to order. We both produce new tools and also rework, although only electroplated and vitrified bond wheels are able to be reworked. All Kemet wheels have a standard precision of ±20 μ for dimension, max. 5 μ for runout and H7 for bore diameter tolerance unless there is a special request. All our products are checked thoroughly and rigidly to ensure their end quality.

New and/or Re-bonding of the used wheels. How does it work?

Customers can contact Kemet, followed by returning the used wheels to Kemet for re-bonding process. Rebonded wheels will not change its quality. Customers can contact our team for more details.

CBN and Diamond Tooling

Core Material Selection

Carbon fibre has become a better choice for core material selection of Diamond and CBN wheel due to its mechanical strength and good vibration dampening characteristic. Using Carbon fibre can reduce wheel weight up to 70 percent. Carbon fibre and/or aluminium is especially recommended for big wheels due to its weight, as being too heavy will impact the motor shaft and its bearings. The principle is that grinding process always produces heat in the contact area between workpiece and the grinding wheels. and the heat produced must be able to be distributed to prevent the grinding wheel from overheating. In addition, grinding with coolant is always recommended since it will prevent the wheel from overheating and will also keep the surface quality better than those without coolant.

CORE MATERIAL VIBRATION DAMPENING HEAT DISSIPATION MECHANICAL STRENGTH
ALUMINUM Poor Very Good Very Good
STEEL Poor Good Very Good
CARBON FIRBE Good Poor Very Good

Industries Served

  • Aerospace
  • Automotive Industry
  • Bearing
  • Compressor/Valves
  • Manufacturing industry
  • Oil & Gas
  • Precision Engineering
  • Pumps

Application of Diamond & CBN Wheel

CBN wheel is used for grinding of all steel materials, Material to be ground must be at least 52HRC of hardness. All other than steel material and meet the condition of hard & brittle must use diamond wheel. Wrong selection of grain will cause poor result on workpiece and or short life of the wheels. Wrong selection could also result in the failure of the grinding process.

  • Brake Industries
  • Engine Valve Grinding
  • Ferrite material
  • Piston Ring
  • Optical Lens, Glass & Polycarbonate
  • Resharpening Cutting Tool
  • Fibre Cement Cutting & Profiling
  • Rubber Belt Grinding & Profiling

Camshaft Paper Roll PCD Tool Grinding

Camshaft Grinding

Paper Roll Grinding

PCD Tool Grinding

Peripheral speed

An increase in wheel peripheral speed causes a decrease in force and thus less form deviation of the workpiece. A decrease in grinding forces means decreased load on the individual grits, which are retained longer in the bond. This increase the life of the wheel. An increase in wheel peripheral speed gives a decrease in chip thickness, with a simultaneous improvement in grit covering by the bond, which in turn results in a decrease in surface roughness. Wear of diamond and CBN grit is to a large extent due to thermal effects. High temperature causes a negative effect on the ability of bonds to retain the abrasive grits. It is generally advisable to use a cutting fluid in the interest of high material removal rate and low wheel wear.

Recommended wheel peripheral speed for Diamond and CBN wheel

Wheel type Wet grinding cup wheels Wet grinding peripheral wheel Dry grinding cup and peripheral wheels
Cerabon 35...70 m/s 35...90 m/s Not recommended
Electroplated 15...25 m/s (D) 15...25 m/s (D) 10...20 m/s (D)
30...100 m/s (B) 30...100 m/s (B) 15...20 m/s (B)

Electroplated Diamond & CBN Tools

Besides the right selection of Diamond or CBN, rpm of the machine’s spindle and right coolant application also play an important role. CBN wheel is used for grinding of all steel materials, Material to be ground must be at least 52 HRC of hardness. All other than steel material and meet the condition of hard & brittle must use diamond wheel. Wrong selection of grain will cause poor result on workpiece and or short life of the wheels. Wrong selection could also result in the failure of the grinding process.