18禁成人黄网站免费观看自慰,久久午夜羞羞影院免费观看,九七年电影院在线免费观看,自拍上厕所一区二区三区黄色视频

Hotline:+86 0635-887779

PRODUCTS

PRODUCTS

Home - PRODUCTS - PRODUCTS

Geological drilling pipe

Geological drilling pipe

"standard

YB/T 5052 China Metallurgical Industry Standard

"use

For geological drilling

》Production specifications and materials

Specifications: 25--356×4--70

Material: DZ40, DZ50, DZ55, DZ60, DZ65,

》Steel pipe manufacturing method:

Hot rolled or cold drawn (rolled)

"delivery status:

Pipes with a yield point of less than or equal to 60 kgf/mm2 shall be delivered at normal temperature; pipes with a yield point greater than 60 kgf/mm2 shall be delivered with normalizing and tempering. Hot-rolled steel tubes can be used to control normal finishing temperatures instead of normalizing.

18禁成人黄网站免费观看自慰,久久午夜羞羞影院免费观看,九七年电影院在线免费观看,自拍上厕所一区二区三区黄色视频