詳細規格及用途描述
* Head: Bugle, Flat, Pan, Hexagon, Hexagon Washer, Other special head
* Thread: AK, BK, CK, SK, CBK, Point No. 1, 3, 5 or 7 and 9
* Recess: Phillips, Square
* Coating: Grey or Black Phosphate, Zinc, Yellow Zinc, and Color Coated such as Ruspert, Green Land,
Xylan KSL or Magni in Gray or Sliver color
