Cross Recess Pan Head Self-Tapping Screw with Washer

Cross Recess Pan Head Flanged Self-Tapping Screw — Product Description

The cross recess pan head self-tapping screw with washer (officially named “cross recess pan head flanged self-tapping screw” in the standard) is a self-tapping fastener with a pan head, a flange washer formed under the head, and a cross recess drive. It is produced in accordance with the electronics industry standard SJ 2501-1984, with thread sizes covering ST2.2 to ST6.3 and product grade A. Its core structural feature is that the pan head and the flange are formed in one piece, so no additional washer is needed during installation, and it can drill directly into materials such as wood, plastic or thin metal sheet and form its own mating thread, achieving fast single-side fastening.

I. Product Features

• Integrated pan head with washer: The head is a pan head with a flange (washer) structure underneath. The washer is embedded before thread rolling and will not fall off the screw, eliminating the step of finding and placing a washer during assembly.
• Cross recess drive: It uses a standard Type H cross recess and fits a PH2 Phillips bit, providing even force distribution and resistance to cam-out, which makes manual or power tool operation easy.
• Self-tapping thread and point: The thread is self-tapping with a pointed tail, and it can press out a mating thread in a pre-drilled hole without the need for prior tapping.
• Standardized material and surface treatment: The standard specifies steel as the material and cites SJ 2496-84 and SJ 2495-84 as the technical basis. Surface treatment is usually zinc plating with passivation, and other coatings can also be negotiated as required.
• Complete size coverage: Thread sizes range from ST2.2 to ST6.3, covering the sizes commonly required in electronics and home appliance assembly.

II. Product Advantages

• Built-in washer protects the base material: The flange washer increases the contact area between the head and the base material, effectively distributing pressure, preventing damage to the surface of the fastened part during tightening, and improving the sealing of the joint.
• Eliminates the washer assembly step: Because the washer cannot fall off, the problem of lost or missing washers in conventional assembly is avoided, which significantly improves work efficiency and is especially suitable for automated mass production.
• Single-side installation for high efficiency: No mating nut or access from the back side is needed, making it suitable for closed structures or assemblies that can only be reached from one side.
• Fits a wide range of base materials: It can be used for joining wood, plastic and thin metal sheet (penetration generally no more than 6 mm, with a maximum of no more than 18 mm), offering flexible application.
• Reliable positioning: The pointed tail design lets the screw position itself quickly at the start of driving, reducing the risk of assembly skew.

III. Application Scope

• Electronics and home appliances: Casing of small home appliances, internal brackets, enclosures of electronic equipment and other assembly points that need the protection of a built-in washer.
• Furniture and decoration: Panel fastening of wooden furniture and panel furniture, as well as installation of gypsum board, MDF and decorative panels.
• Thin sheet metal joining: Joining between color-coated steel sheets, or fastening of color-coated steel sheet to purlins, wall girts and other thin sheet structures.
• Hardware and DIY: Installation of hardware such as hinges, handles and locks, as well as handmade model making.