Bent eye screws

a) DIN 912 (ISO 4762) 是指公制內六角螺絲的特定標準, 也稱為杯頭螺絲, 具有圓柱形頭部, 中心有六角形凹槽 (Socket), 可以使用內六角扳手 (Hex Key or Allen Wrench) 將其旋緊或鬆開. 這些螺絲通常用於需要高拉伸強度的各種應用。

b) 帶滾花頭的內六角螺絲是 DIN 912 的變化型，頭部周圍具有滾花紋理表面。這種設計提供了更好的抓握力，便於手動操作或調整，特別適用於需要頻繁調整的應用場合。

a) DIN 968 制定了帶華司盤頭十字孔自攻螺絲的標準。這些螺絲通常搭配兩種類型的孔型：H 型（十字槽 phillips）和 Z 型（米字槽 pozidrive), 兩者均設計用於輕鬆安裝和拆卸。

b) DIN 7970 自攻螺絲規範中 亦制定了兩種類型的螺紋尾端：C 型（錐型尾 cone point）和 F 型（平尾 flat point）。

a) A self-tapping screw for thermoplastics is a specialized fastener designed to create its own threads as it is driven into plastic materials.

b) These screws have wider, sharp, and deep threads, which allow them to cut into the softer thermoplastic material efficiently, creating a secure, long-lasting hold.

With small collar around body shank

Thin hexagon head 

a) A ribbed neck screw is a type of fastener designed with a special feature on its shank or neck. Instead of a smooth or threaded surface, the neck of the screw has ribbed, serrated, or knurled features. These ribs or serrations provide additional grip and resistance when the screw is driven into a material, preventing it from rotating or loosening.