Cross Slotted Pan Head Screw with Flat Washer Assembly

Cross Slotted Pan Head Screw and Flat Washer Assembly — Product Introduction

The Cross Slotted Pan Head Screw with Flat Washer Assembly (referred to as “Two-Piece Assembly Screw”) is a fastener that combines a cross slotted pan head screw and a flat washer pre-assembled together. It is manufactured according to the GB/T 9074.1 standard (equivalent to ISO 10644), suitable for assembly screws with thread sizes from M2 to M12. The screw performance classes include 8.8, 9.8, and 10.9, while the flat washer hardness classes are 200 HV or 300 HV. The washer is pre-installed on the screw at the factory and can rotate freely without falling off, eliminating the need to handle the washer separately during installation and significantly simplifying the assembly process.

1. Product Features

• Pre-Assembled Integrated Design: The screw and flat washer are pre-assembled before leaving the factory. The washer can rotate automatically without detaching, preventing loss or omission of washers during assembly.
• Cross Slotted Drive: Features a standard cross slot type, compatible with PH-type cross screwdrivers or power bit tips. Torque transmission is stable and operation is convenient.
• Complete Specification Coverage: Thread sizes range from M2 to M12 with a wide nominal length range, meeting fastening needs for panels of varying thickness.
• Diverse Materials and Grades: Options include carbon steel (such as 1010, 1018, 10B21) and stainless steel (SUS304). Carbon steel parts can undergo environmental-friendly blue-white zinc, colored zinc, or nickel plating surface treatments. Stainless steel parts are generally supplied in natural finish or passivated.
• Defined Washer Hardness Grades: Flat washer hardness is divided into two grades — 200 HV and 300 HV — allowing selection of the appropriate washer based on the hardness of the joined material, preventing crushing of the base material.

2. Product Advantages

• Significantly Improved Assembly Efficiency: The integrated washer and screw supply eliminates the manual step of threading a washer, particularly suited for automated production lines and high-volume assembly operations.
• Prevents Washer Omission: The pre-assembled structure fundamentally prevents connection loosening or base material damage caused by missing washers, improving assembly quality consistency.
• Protects the Joined Surface: The flat washer increases the contact area between the head and the workpiece, evenly distributing pressure and reducing damage to painted surfaces, soft materials, or thin sheets.
• Reliable Connection: With appropriate tightening torque, the assembly provides stable clamping force. Some models, through the fit between washer and screw, also offer a certain degree of anti-loosening effect.
• Standardized Interchangeability: As a national standard product, dimensions are unified and qualified products from different suppliers are interchangeable, facilitating procurement and spare parts management.

3. Scope of Application

• Electronics and Home Appliances: Small electronic products, household appliances, inverters, terminal blocks, and other applications requiring rapid assembly with surface protection.
• Machinery and Electrical: Fastening connections for machinery enclosures, control cabinets, electrical panels, instruments, and meters.
• Furniture and Decoration: Metal furniture, office furniture, display racks, and other assembly areas requiring built-in washer protection.
• General Industrial Assembly: Fastening scenarios for various thin-plate structures, brackets, cover plates, and other situations requiring cross slotted pan head screws with flat washers.