Polycrystalline Diamond (PCD) Form Tools


Recent years have seen the adoption of Polycrystalline Diamond (PCD) form tools, characterised by their free cutting ability and long life, for many applications especially in the wood work industry, plastics industries and automotive an aerospace industries. PCD is now the first choice for machining materials such as MDF, laminated chipboards and many of the glass filled epoxy resins, silica aluminium castings and MMCs. Hamilton Lichfield manufacture a complete range of these tools the great majority of which are to customers' specific requirements. The following notes offer a guide to the choice of tools available and to our standard products.

Advantages of PCD

There now exists many video and written case histories to demonstrate the considerable advantages that may be expected from PCD when used on the correct application. These may be briefly stated as follows:-

1. Exceptionally long production runs between tool relaps when compared to other tool types. This leads to enhanced cost effective production with reduced machine down time and consequent savings in tool stock holding.

2. Tighter tolerances may be held throughout the extended life cycle of the tools giving more consistent finished components.

3. Usually higher component finishes are obtainable than with conventional tooling.

Tool Construction

Tool bodies can be manufactured in a variety of grades of steel or tungsten carbide or advanced ceramics. The PCD/PCBN can be formed to the tool in either single or multiple segments. Tool geometry can be varied significantly to enhance the cutting performance of the PCB with a wide variety of materials to be cut.. A typical example being high shear angles for machining MMCs

Formed Routers

There are many applications that require a profiled router, particularly in the woodworking industry such as panel raising and Ovolo cutters, the figure below shows a typical example.

Hamilton Lichfield employ computer aided design in the manufacture of this type of tooling to ensure optimum utilisation of the PCD. In production a variety of techniques including CNC wire erosion, die sinking and lapping are used to ensure that perfect profiles with keen cutting edges are obtained. Where necessary Hamilton Lichfield routers are balanced after manufacture to ensure optimum performance on all modern high speed routing machinery, this is of particular importance with single flute routers.

All styles of formed router are available to order and we are equally happy to work from tool or component drawings, samples of existing tooling or from the required formed component.



  1. Polycrystalline diamond is very wear resistant but also BRITTLE; it may be chipped very easily particularly by metal objects, spanners etc. Always handle the tools carefully and keep in a protective box when not in use.
  2. The tools are most vulnerable when being installed or removed from the machine. It is advisable to protect the cutting edges when carrying out these operations, a wooden block bored to suit the tool is a convenient method.
  3. After setting the tool always carry out a short test cut to ensure that the correct depth of cut has been programmed.
  4. When the tools are ready for relapping they may become blunt and even chip; tools should not be left running in this condition as more extensive damage may occur.
  5. Bluing of the steel shank, due to the build up of excessive heat and also increasing cutting noise are often good indicators of the state of the tools that are ready for servicing. Please return for repair before excess use renders them scrap.