Pin Hole

Pin-hole

central test hole

curtain grouting test hole

needle hole test

Open Hole Test

percussion test hole

scour hole test

Test Hole

water injection test hole

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

Agglutination test in test tube