特殊薄頭螺絲

a) ISO 7380-2 訂定了帶有華司的內六角圓頭螺絲標準。通用內六角梅花孔（6 lobe）設計是另一種在各種應用中廣泛使用的常見替代方案。

b) 此螺絲在牙尾末端有一個延伸的圓柱形尖端( 通稱為狗尾 dog point), 其作用為可在對接的部件中做到精確地對準與定位。

Serrations under head / Hexalobular socket ISO 10664

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.

a) DIN 7500 specifies self-tapping screws for metal, also known as thread-forming screws. These screws are designed to form or cut threads in a pre-drilled hole in metal materials, without requiring a pre-cut thread.

b) The screw shank has a three-lobe shape instead of a round cross-section, which reduces friction during installation, and facilitates smooth material displacement and efficient thread formation.

c) The long dog point (the extended, unthreaded tip of the screw) acts as a pilot, helping to align the screw with the pre-drilled hole during installation, and faciliates smooth installation.

d) A standard trilobe thread forming screw without dog point is avaialble upon request.

a) This bolt features an external hexalobular socket with a small flange, and is designed for applications requiring a high torque transfer with reduced risk of cam-out. 

b) The star-shaped head allows for great torque transfer by distributing the load more evenly across the drive, compared to traditional drive systems like Phillips, Pozi or slotted.