10.9 grade carbon steel black plated pan head cross slot captive screw (GB818 standard, round head anti-loosening half-thread thin rod) is a high-strength, anti-loosening precision fastener. The following is a detailed description of its customization requirements. The content is layered according to technical logic, and the key parameters are highlighted
The core value of this screw lies in the balance of high strength, anti-loosening, and precision adaptation. It is suitable for industrial fields that require both reliability and installation accuracy.
1. Basic standards and specifications
Implementation standard: GB818, it is necessary to clarify whether it is a full thread or a half thread
Performance level: 10.9 grade (carbon steel material, tensile strength ≥1040MPa, yield strength ≥940MPa)
Surface treatment: black plating (black zinc coating/black oxidation, salt spray test requirements must be indicated, such as 72h neutral salt spray)
2. Structural parameter customization requirements
Head type: pan head with cross slot, using ISO 7045 standard slot type
Anti-loosening design: nylon washer pre-installed or metal locking gasket; the material must be specified.
Rod design: thin rod, half-thread. Bare rod diameter ≤ thread minor diameter, thread length ≥1.5d.
Thread specification: Metric thread (such as M3-M8), fine thread needs to be marked with pitch
Total length: 10-50mm (incremented by 1mm, specific size table needs to be provided)
III. Material and process requirements
Material: SCM435 or equivalent 10.9 grade alloy steel
Hardness: HRC 32-39
Anti-loosening treatment:
Pre-set PA66 nylon ring (temperature resistant -40℃~+120℃)
Double-stack metal locking gasket (304 stainless steel)
Surface treatment details
Coating thickness: black zinc layer ≥8μm
Optional additional requirements: anti-rust oil
IV. Key quality control points
Torque test: assembly torque ≥ standard value
Anti-loosening performance: Vibration test, according to GB/T 10431 standard, 2000 cycles without loosening pass.
Appearance: uniform coating without exposed bottom, cross groove without burrs
V. Packaging and Labeling
Packing method: PVC blister tray in inner box (100pcs per tray), 5000pcs/box in outer box (adjustable)
Labeling content: laser marking (including 10.9 grade, batch number, manufacturer code)
VI. Additional service requirements
Certification requirements: If a RoHS/REACH compliance statement is required
Delivery cycle: 15 days for mold development (after first sample confirmation), 30 days for mass production
Acceptance method: Sampling inspection according to GB/T 90.1-2015
It is recommended to provide drawings or samples to confirm key dimensions, such as head diameter K value and cross groove depth to avoid ambiguity.
