Shield cutters can be roughly divided into two categories according to their rock breaking methods: shield cutters and scrapers.

1. Shield cutters: Cutters refer to rock-breaking cutters that not only rotate with the cutter disc but also rotate at the same time during the excavation process.

According to the installation position, cutters can be divided into positive cutters, center cutters, side cutters, and hole-expanding cutters;

According to the material of the blade, cutters can be divided into all-steel cutters and carbide-insulated cutters;

According to the shape of the blade, cutters can be divided into: disc cutters (steel cutter ring cutters and ball tooth cutter ring cutters), tooth cutters (steel teeth and ball 

teeth);

According to the structural form, cutters are divided into single-edge cutters, double-edge cutters, three-edge cutters, two-joint cutters, three-joint cutters, and eccentric 

cutters.

2. Scrapers: Scrapers refer to rock-breaking cutters that only rotate with the cutter disc and do not rotate at the same time during the excavation process.

There are various types of scrapers. Currently, the commonly used ones on shield machines include edge scrapers, cutting knives, toothed knives, leading knives, contour 

knives, scrapers, etc.