A shrinkage method combining with medium-length hole and shallow hole

hole by hole blasting

hole by hole blasting technique

hole by hole detonating

hole by hole initiating

hole by hole initiation

Hole-by-hole

mid-and-deep hole combining shallow hole balsting

sight hole peep hole

box plate tappet

box tappet

built-up tappet

chain tappet

heart shaped tappet

inside tappet loom

Jamieson’s tappet

negative tappet

outside tappet

picking by tappet

picking tappet