Diamond is used because it is the hardest known material - about four times harder than aluminium oxide and twice as hard as CBN. It can easily grind away the surface of any grinding wheel specification.

  In comparison to single or multi-point diamond form dressing, Saint-Gobain Abrasives diamond Rotary Truers perform more functions and offer many more benefits:

We can provide the customer with a complete package including Truer, Drive Unit and Coolant Delivery Systems.

  In comparison to single or multi-point diamond form dressing, Saint-Gobain Abrasives diamond Rotary Truers perform more functions and offer many more benefits:

•  True, dress and condition the grinding wheel in one operation
•  Enable complex, tight tolerance forms to be ground effectively
•  Improve ground part accuracy down to around 1 micron
•  Reduce machine down time and increase capacity
•  Improve process control
•  Improve quality consistency and reduce reject rates
•  Enable maximum automation of the grinding process
•  Reduce dressing time and optimise wheel life
•  Reduce overall costs per part ground

  When it comes to the design of the diamond layer, Saint-Gobain Abrasives offers an unbeatable advantage. It is the only industrial diamond toolmaker in the world with access to the unique industrial diamond ‘sights’ through which the majority of the world’s output of natural diamond is initially traded.

  Saint-Gobain Abrasives also has over 100 years of experience in diamond technology and an in-depth understanding of diamond selection.  As a result, the most effective performance results are easily within reach.

Diamond size

  Saint-Gobain Abrasives selects diamonds in relation to the size of the geometric profile features and according to the ground part surface finish required. Different diamond sizes can be combined to create optimum performance.

Diamond type

  To ensure that the best quality of natural diamond is selected, Saint-Gobain Abrasives closely evaluates the source and the processes used in its production. Saint-Gobain Abrasives can use special diamond shapes such as cubes and triangles for reinforcement in profile areas subject to preferential wear.

Diamond concentration

  This is selected according to the cutting action required. Low diamond concentration is used for higher stock removal and is suitable for large diameter truers where dressing forces could become excessive. 

  More densely packed diamond is more appropriate where a finer finish is needed or where long life is important. However, as dressing forces increase with diamond concentration, these truers need rigid machines to operate satisfactorily. 

  Saint-Gobain Abrasives can set diamonds in different patterns for additional effects during use and because the diamonds may be set individually by hand, special requirements for diamond-free areas for coolant and debris control can easily be met. 

  Additional design considerations include bore diameter, which Saint-Gobain Abrasives makes to fit the largest acceptable spindle, for adequate rigidity.

  Saint-Gobain Abrasives professional designers and application engineers work closely with customers, particularly at the final component design stages. Using a wealth of experience in ‘design for manufacture’ discussions, they help to achieve grinding process optimisation and to produce quality results at the lowest unit cost.

By using a wide choice of design methods and working alongside customers, Saint-Gobain Abrasives can design and build rotary truers for any application.

  To suit customer requirements, Saint-Gobain rotary truers can be manufactured using the following three methods.

Reverse Electroplating - for accuracy

  A layer of nickel is electroplated onto the internal surface of a hollow cylindrical mould, to hold a single layer of diamonds firmly in place.  A steel body is fitted then the mould is removed, exposing the diamond surface. Because all of the diamond cutting points lie on the "surface of revolution" created in the mould machining operation, this method produces the most accurate type of rotary truer available.

Infiltration - for durability

  A mould, similar to that needed for reverse plating, is created and diamonds are fixed to the internal mould wall. A blend of hard metal powders is then packed inside the mould cavity, together with a steel core.  Liquid metal is made to infiltrate the powder bed and this consolidates the power around the diamond layer.

  Due to thermal movement during the heat treatment process, it is usually necessary to grind the diamond surface of the tool to achieve the profile accuracy and roundness tolerances, which are generally less demanding that in reverse plating products.

The metal matrix is very hard wearing, which creates the most durable type of truer.

Direct Electroplating - for economy

  Diamond are fixed to an accurately machined steel body, rather than creating a mould. These type of truer offer great economy and are available in short lead times. They are well suited to low volume applications and prototype development where the geometry is not difficult, tolerances are open and tool life is not a priority.

  When the rotary truer is finally completed, Saint-Gobain Abrasives inspects the finished product under the following precisely controlled conditions, to ensure compliance with order requirements.

  Completed truers are set up on rigid test grinding machines and used to profile Saint-Gobain Abrasives precision vitrified grinding wheels. Test pieces are then ground to determine profile accuracy.

  Other features, such as bore roundness, straightness and parallelism are measured from the truer itself in climate controlled metrology facilities. If desired, customers can receive the inspection drawings and the test piece with the finished product.