bleed screw hole

instantaneous screw axis

narrow hinge without screw hole

n-fold screw axis

quaternary screw axis

Same-Direction and Double-Axis Screw

Screw Axis

screw axis of symmetry

Screw Hole

screw hole machining

ternary screw axis

axis hole

hole axis

hole hole interaction

Axis axis

Positioning Screw， Set Screw

right hand screw [= right handed screw]

screw hexagon socket head cap screw

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

electron-hole liquid drop (=electron-hole droplet)