Dongguan Wofu Hardware Products Co., Ltd. is located near Songshan Lake in Dongguan. The company specializes in a wide range of hardware components, including hardware and fastener parts, home appliance accessories, electromechanical components, high-speed rail accessories, and photographic prime-lens accessories, as well as other machined metal parts. Due to the needs of our business, many colleagues in various positions are not familiar with self-tapping screws. To help everyone better understand their manufacturing process and structural design, the company has invited a professional technical engineer specializing in the design of self-tapping screws to give a presentation on this topic.

Cross-recess countersunk self-tapping screws are a type of screw characterized by their flat-head, countersunk-head, or half-countersunk-head designs. Typically, countersunk screws feature a cross-recess slot—this is precisely the standard specification outlined in the national standard, identified by the national standard number GB/T 846-1985. Countersunk screws are commonly used in power equipment, electronic machinery, mechanical equipment, household appliances, digital products, hydraulic engineering, interior decoration and construction, and many other applications. Generally, countersunk screws are made from metal wire stock that is first forged into shape and then threaded. After forming, they take on a cylindrical appearance, with a flat head featuring an inclined surface around the screw’s side, enabling the screw to securely fasten to nuts or other components.

The head of a countersunk screw has a larger diameter and can be either round or hexagonal, allowing tools such as screwdrivers or wrenches to turn the screw. The more prominent head also prevents the screw from being driven too deeply into the material, thus avoiding penetration through the workpiece, and enhances the screw's clamping force on the material. Countersunk screws can usually be removed or re-tightened at will without compromising their effectiveness; they also provide greater holding power than nails and can be reused multiple times. On materials where countersunk screws are used, the screw head can fully sink into the surface, ensuring that it does not interfere with the function of the assembly.

On consolidated materials, it can use its own threads to "tap, drill, squeeze, and press" corresponding threads into the consolidated body, enabling them to fit together tightly.

Structural elements

A self-tapping screw consists of three main parts from head to tip: the head, the shank, and the end of the shank. Each self-tapping screw is composed of four key elements: head shape, drive type, thread type, and end configuration.

Processing material

Carbon steel 1022, stainless steel 304, stainless steel 316, stainless steel 410

Heat treatment

Our company provides self-tapping screws made of carbon steel 1022 and stainless steel 410, both of which undergo heat treatment processes.

Surface treatment

Galvanized, Hot-Dip Galvanized, Disk, and others—depending on user requirements, the salt spray resistance can be as long as 2,000 hours.