摘要 |
The shank of a self tapping screw has a thread forming section, a threaded section, and a reduced diameter section interconnecting the forming and threaded sections. The thread forming section forms internal threads into a known thread form that has a wedge ramp at its root. The threaded section comprises threads of standard form having the same pitch as the thread forming section. The reduced diameter section is slightly longer than an integer multiple of the pitch so that the threaded section is backset slightly from the forming section. |