The hardness of a cutting disc refers to how resistant the bonding material is to wear and how tightly it holds the abrasive grains. This hardness is crucial as it influences the disc’s lifespan, performance, and the type of materials it can cut effectively.
A harder disc has the abrasive grains more tightly bonded, meaning they are held in place longer before being released. This makes the disc more durable and wear-resistant, making it ideal for cutting softer materials. On the other hand, harder discs may heat up more quickly because the grains don’t break away as easily to expose new, sharp grains.
Conversely, a softer disc has a bonding material that allows the grains to break away more easily. As the grains break away, new, sharp grains are exposed. This allows the disc to remain sharp and cool as it is used, making it suitable for cutting harder materials. However, softer discs tend to wear out more quickly than harder discs.
The hardness of a cutting disc is typically designated by a letter from the alphabet. ‘A’ is for a softer bond, while ‘Z’ indicates a very hard bond. This hardness scale can vary among manufacturers, so it’s always best to refer to the manufacturer’s information.
When choosing a cutting disc, consider the hardness in conjunction with other factors such as the type of abrasive, grain size, and the material you intend to cut to get the best performance.