The stylus is an important part of the measuring system. During the measurement, the stylus is in direct contact with the part. Hollow ball styli are mostly used to benefit from the low form deviation of a sphere without the need to carry the full weight of a solid sphere. This kind of tip is used to measure deep holes and rough surfaces and is usually made from ceramics.
Ceramic styli tips are primarily used for long or heavy styli and disc styli. Due to their resistance to wear, ceramic styli are often used for scanning extremely rough surfaces, such as cast iron.