石油管外螺纹硬质合金刀杆
carbide tool shank for petroleum pipe external threading
SAE干式密封短外锥管螺纹
dryseal sae short external taper pipe thread
内螺纹外翅片铸铁管
Casting tube with female screw and side fins
内螺纹外肋片铸铁换热管
Cast iron heat exchange tube with inner corrugation and outer fins
外螺纹铜管
Outer-Spiral-rib copper tube
外螺纹凸缘套管
flanged sleeve with external thread
美国标准锥管螺纹管内螺纹
nptf internal pipe thread