Replaceable Cutter Bit is one kind of Pre-cutting Bit. It can be installed in the Disc Cutter Holder to replace Disc Cutter in smaller-diameter gravel or intensely weathered rocks conditions. Replaceable Cutter Bit and Disc Cutter are spaced or alternated with each other in complex ground, so that Cutter Head can keep best composition during tunneling.

Cutter Holder is the connection of cutter and Cutter Head, which facilitates the cutter replacement.

Central Cutter Bit is used to cut the central soil of excavation face. The role of Central Cutter Bit is to center the excavation face and loosen the soil.( The characteristics of Central Cutter Bit are: 1. The body of Central Cutter bit is higher than other cutters, which ensures it first to cut soil. 2. Fishtail Cutter is tapered, so the soil cut by Central Cutter bit not only move along tangent direction and radial direction, but also rotate.)  Central Cutter Bit can cut the central section soil and improve the fluidity of soil, so it can greatly increase Shield Machine tunneling efficiency.

Ordinary Cutter Bit is soft ground tool, it generally used for loose strata conditions like silt, fine silt, clay, medium sand, coarse-grained sand and gravelly sand layers. Cutter Bits are installed on the opening slots of Cutter Head and used for excavating most of the sections. While Shield Machine is moving forward, the Cutter Bit is rotating with Cutter Head. The rotation movement drives cutter edge and tool bit into soil and form axial shearing force( tunnel forward direction) and radial shearing force(tangential direction of Cutter Wheel) to do the excavation.

Heavy-duty Cutter Bit is mainly used in hard rock stratum or complex strata containing sandy gravel with big diameter, gravel and sandy clay. Its role is to remove the muck to protect Roller Disc Cutter and Pre-cutting Bit body.

Scraper Bit is one kind of Cutter Bits which is installed on the extreme edge of Cutter Head. It is used to cut the soft soil around the Cutter Head to keep the same excavation diameter. It is also to remove the stone slag crushed by Disc Cutter and Pre-cutting Bit in the hard rock stratum and complex strata .