Screw The Value
Primarily to make industrial products composed of a fixed one, in use often occurred between the tooth and the tooth cannot be secret, too forcibly locking the screw head separation, or a poor tooth pattern lock tight and so failed to meet the conditions of use, both for the quality of precision. Screws are "product" rather than hand-made work of art, in mass production, in order to achieve high accuracy and stability of quality and prices to consumers for the purpose of popularization. Precision of screw is usually 6g (level 2, United States specifications "IFI" 2A), construction projects using 8g shell of the crude level (level 3, "IFI" teeth for 1 a). Screw values is very important, because screw caused by poor quality car factory in the world of bankruptcy case also because screws in plane crash caused by poor vehicle example of subversion.