亚洲狠狠做深爱婷婷影院,欲色天天网综合久久,精品一区二区久久久久久无码,又色又爽又黄又粗的视频免费观看

Metric Spanner Specification mm Screw specifications Inside hexagonal cylindrical head screw (cup head) Hexagonal countersunk head screw (flat cup) Internal hexagonal semicircular head screw (round cup) Internal hexagonal fastening screw (m...

GB8 square head bolt GB10 countersunk square neck bolt GB11 countersunk tenon bolt GB12 semi-circular head square neck bolt GB13 flat round head tenon bolt GB14 large semi-circular head square neck bolt Bolts for GB27 Hexagonal Head Hinged...

British thread Round pipe threads Thread diameter （ inch ） Number of teeth per inch Bit diameter （ millimeter ） Thread diameter （ inch ） Number of teeth per inch Drill diameter （ millimeter ） Cast iron, brass, bronze steel,...

Dacromet is a metal surface treatment method. It was originally developed by Michael Martin, an American scientist, and then transferred to DIAMOND SHAMROK. It is a new member of the anti-corrosion system of metal surface. It has been paten...

1. Overview of Steel Number Representation in China The steel grade is abbreviated as steel grade. It is the name of each specific steel product. It is a common language for people to understand steel. According to the national standard Ste...

According to the German standard DIN50150, the following tables are used to compare the tensile strength with Vickers hardness, Brinell hardness and Rockwell hardness. If you want to check the tensile strength 1000N/mm2, or Vickers hardness...

英制 公制 英制 公制 英制 公制 英制 公制 分數 小數 mm 分數 小數 mm 分數 小數 mm 分數 小數 mm 0.0004 0.01 0.3 7.620 0.7874 20.000 1.969 50 0.001 0.025 5/16 0.3125 7.938 51/64 0.7969 20.241 2 2.000 50.8 0.0039 0...