螺旋升液混合沉降器

captive screw

hexagonal screw

TAPPING metal or other material [= screw-threading]

screw magazine

acme screw thread【机】;trapezoidal thread【机】

instantaneous screw axis

lead screw cutting lathes【机】;lead screw lathe【机】;lead screw turning machine【机】

screw jaw with lug