oval piston pine hole OPPH
Piston Noncircular Pin-hole
piston pin bushing oil hole
Special Piston Pin Hole
A shrinkage method combining with medium-length hole and shallow hole
electron-hole liquid drop (=electron-hole droplet)
hole by hole blasting technique
hole by hole detonating
hole by hole initiating
hole by hole initiation
hole-by-hole detonation