What Is a Firmer Chisel?

Chiseling a large mouth is also called "file large mouth". Well salt salt well drilling process. After the stone circle is laid, the inner diameter of the stone circle is taken as the standard. The white water penetrates the section until it reaches the hard rock layer. During the Ming and Qing Dynasties, the Sichuan well drilling process was divided into seven steps: selecting well location, opening the well, lowering the stone circle, cutting the big mouth, lowering the bamboo, cutting the small mouth, and mud. The depth of the mouth varies from region to region. For chiseling large mouths, fishtail files are generally used. ^[1]