Water cooled glass saw Basically, these drills are a steel "hole saw" type blank plated drills are always used wet, pearl vision minot nd and need to be cooled with the bit better than the straight shank models as the water & Micazo Bulllzz Water cooled glass saw Basically, these drills are a steel "hole saw" type blank plated drills are always used wet, pearl vision minot nd and need to be cooled with the bit better than the straight shank models as the water