Flat Shoulder Bolt Phillips Hexagon Neck Metric Thread

Flat shoulder bolt is the bolt with flat head and hexagon shoulder under the bolt. Flat shoulder bolt is a screw with an unthreaded shoulder that is larger in diameter than the threads. Also known as stripper bolt. The cylindrical shoulder that allows for the rotation of attached parts like pulleys, gears, moving parts of engines and mechanical assemblies, and rolling wheels. Shoulder bolt also used to attach stripper plates. The socket head enables high torque fastening with limited clearance. Ever Hardware provides custom-made fasteners and customizable packaging.

The Phillips screw drive was created by John P. Thompson, who after failing to interest manufacturers, sold his design to businessman Henry F. Phillips. Phillips is credited with forming a company (Phillips Screw Company), improving the design, and promoting the adoption of his product. The original patent expired in 1966, but the Phillips Screw Company continued to develop improved designs.
Phillips drive bits are often designated by the letters “PH”, plus a size code 0000, 000, 00, 0, 1, 2, 3, or 4 (by order of increasing size); the numerical bit size codes do not necessarily correspond to nominal screw size numbers.

A bolt is a form of threaded fastener with an external male thread. Bolts are thus closely related to, and often confused with, screws.
The distinction between a bolt and a screw is unclear and commonly misunderstood. There are several practical differences, but most have some degree of overlap between bolts and screws.
The defining distinction, per Machinery’s Handbook, is in their intended purpose: Bolts are for the assembly of two unthreaded components, with the aid of a nut. Screws in contrast are used with components, at least one of which contains its own internal thread, which even may be formed by the installation of the screw itself. Many threaded fasteners can be described as either screws or bolts, depending on how they are used.