What are the thread types of the phillips flat head screws?
There are two major types of screw types, one is a machine thread and the other is a self-tapping. So what are the thread types of the phillips flat head screws? copper phillips flat head screws - self tapping sharp tail carbon steel blue zinc plated phillips flat head screws - machine thread carbon steel black zinc plated phillips flat head screws - machine half thread carbon steel nickel plated phillips flat head screws - self tapping flat end www.sstls.com www.szsst88.com