Countersunk Head Blue-White Zinc Plated Self-Drilling Screw (Chinese National Standard: Phillips Countersunk Head Self-Drilling And Self-Tapping Screw GB/T15856.2-2002)

1. Applicable fields and Chinese national standard basis

This product is produced in strict accordance with the GB/T15856.2-2002 national standard. It has a 90° countersunk head Phillips recess structure. After locking, the screw head sinks completely into the interior of the board, leaving a smooth surface with no bulges. It is mostly used in the assembly of light steel keel ceilings, door and window hardware, interior sheet metal, light steel frames, furniture iron sheet connectors, and aluminum alloy auxiliary materials. The products are exported in batches to the Middle East, Southeast Asia, Africa and other overseas hardware and building materials markets all year round. It comes with a drilling end, eliminating the need for pre-drilling. It can drill through thin steel sheets and self-tapping wooden plates, making it a dual-purpose machine.

2. Material Selection and Production Process

The raw material is high-quality carbon steel and has undergone overall quenching heat treatment. The hardness of the drill point cutting edge reaches the standard, the drilling is sharp, and the drilling is resistant to chipping or break at the drill point. Production process: eleven processes of rough drawing of raw materials, annealing, phosphating, fine drawing, cold heading, point forming, thread rolling, heat treatment processing, zinc plating, washer assembly, and packaging. The Phillips recess groove is standard and is suitable for universal Phillips bits. The installation is not easy to slip and recess damage; the thread pitch is based on the Chinese national standard parameters. When screwed into the base material, the engagement is firm and it is resistant to loosening under long-term vibration conditions. The blue zinc electroplating layer is dense.

3. Product core advantages

90° countersunk head hidden installation: tapered countersunk head structure, the screw head surface is flush with the workpiece after tightening, and there are no exposed protrusions. It is preferred for interior decoration and home decoration projects that require smooth appearance.

Chinese national standard self-drilling dual-purpose performance: Strictly benchmarked against Chinese national standard drilling parameters, it can directly drill 0.7~6mm thick cold-rolled steel sheets and zinc plated iron sheets. It is also suitable for fastening solid wood, density boards, and plastic parts, reducing the number of customer stock items.

4. Quality control warehousing and supporting services

All Chinese national standard specifications are in stock, regular orders are dispatched within 48 hours, and small-batch samples and full-container export orders can be accepted. Before leaving the factory, the drill point hardness, Phillips recess strength, thread accuracy, coating adhesion, etc. are randomly inspected one by one according to Chinese national standards, and defective products such as chipped heads and incomplete tooth patterns are eliminated. It can be packaged in complete sets with our factory's flat washer and spring washer, providing one-stop fastening accessories; it supports customized extended and special-shaped nonstandard self-drilling screws according to drawings or samples, and stable production capacity ensures long-term order renewals for overseas customers.