Product Description
Renishaw M4 6 mm Ruby Ball Star Stylus - Ceramic Stem (L 100 mm EWL 88.5 mm)
Star Styli
These are multi-tip stylus configurations with rigidly mounted styli. Balls are made from ruby, silicon nitride or zirconia. You can also configure your own star styli using stylus centers to mount up to 5 styli components.
Their main application is for surfaces and holes with which direct contact can be made. This configuration gives flexibility, enabling the tip to make contact with different features without changing the stylus.
Ruby Ball Material
The industry standard and the optimum stylus ball material for a vast majority of measurement applications, ruby is one of the hardest known materials. Synthetic ruby is 99% pure aluminium oxide which is grown into crystals (or “boules”) at 2000 °C using the Verneuil process. The boules are then cut and gradually machined into a highly spherical form. Ruby balls are exceptionally smooth on the surface, have great compressive strength and a high resistance to mechanical corrosion.
Very few applications exists where ruby is not the preferred ball material, however there are two applications where balls manufactured from other materials are recommended.
The first is for heavy duty scanning applications on aluminium. Because the materials attract, a phenomenon known as ‘adhesive wear’ can occur which involves build up of aluminium from the surface onto the ball. A better ball material for such applications is silicon nitride.
The second is in heavy duty scanning applications on cast iron. Interaction between the two materials can result in ‘abrasive wear’ of the ruby ball surface. For such applications, Zirconia balls are recommended.
Ceramic Stem Material
For ball diameters greater than 3 mm, and lengths over 30 mm, ceramic stems offer stiffness comparable to steel but are significantly lighter than tungsten carbide. Ceramic stemmed styli can also offer additional crash protection to your probe as the stem will shatter in a collision.
Please contact us if you require any styli with special ball materials. We can recommend the most suitable material for scanning different materials.
Part number: A-5000-6462
