What is the hardness of sandpaper and how does it affect the grinding effect?

The "hardness" of sandpaper is a crucial performance measure. It's directly linked to how firmly and durably the abrasive particles are on the sandpaper's surface. This feature not only influences how long the sandpaper lasts but also really decides how well and what quality the grinding job turns out.
Sandpaper with high hardness means its abrasive particles are stronger and don't come off easily. This kind of sandpaper is great at wearing down hard materials like metal or hard wood. It can get rid of blemishes on the material surface fast and make the grinding work go smoothly. But high hardness might also make it not so good at handling details, especially when it comes to complex shapes or when you need really fine grinding. Its flexibility could be limited.
On the other hand, sandpaper with low hardness is good because it's more delicate and adaptable. The abrasive particles in this type of sandpaper are softer and fit the material surface better. It's especially useful for soft materials or when you need to do fine grinding. Low-hardness sandpaper can give a smoother and more delicate grinding result. At the same time, its better flexibility makes it easier to handle complex shapes. But the durability of low-hardness sandpaper is not as strong, and you might need to change it more often.
When you pick sandpaper, you need to think about what you need to do and the features of the material. Matching the hardness of the sandpaper right with the grinding task can not only make the work go faster but also make sure the grinding is good and you get the best result.