1. Background: Vibration Challenges for Drone Flight Control Boards

During flight, drone flight control boards are continuously subjected to high-frequency vibration loads. Especially for multi-rotor drones during hovering, acceleration, and turning maneuvers, vibration frequencies can reach 50-500Hz with acceleration peaks exceeding 10g. Traditional screw fastening solutions are prone to loosening under long-term vibration environments, leading to electrical connection failures of flight control boards and seriously affecting flight safety.

ZHUHAI JIALI HARDWARE CO., LTD. has developed the PMS-LK series locking screws based on ISO 10664 standard, specifically designed for anti-vibration fastening requirements of high-precision electronic equipment such as drone flight control boards.

2. ISO 10664 Torx Anti-Loosening Structure Analysis

ISO 10664 standard defines geometric parameters and mechanical performance requirements for hexalobular (Torx) fasteners. JIALI PMS-LK series incorporates optimized innovations based on this standard:

• Six-Point Contact Drive: Compared to four-point contact of traditional Phillips drive, Torx structure achieves six-point uniform force distribution, increasing torque transmission by 30%, effectively preventing cam-out and stripping.
• Radial Pressure Distribution: The lobed profile generates radial expansion force during tightening, creating interference fit between thread flanks, achieving mechanical self-locking.
• Low Friction Coefficient: Dacromet coating treatment maintains stable friction coefficient at 0.12-0.14, ensuring precise preload control.

3. 10⁷ Cycle Vibration Test Data

ZHUHAI JIALI laboratory conducted accelerated vibration testing on PMS-LK series M3×6 specimens:

• Test Conditions: Frequency 100Hz, acceleration 15g, amplitude 1.5mm, ambient temperature 25℃
• Test Cycles: 10⁷ cycles (approximately equivalent to 5000 hours of cumulative drone flight)
• Initial Preload: 2.5 N·m
• Test Results:
  • Torque retention after 10⁶ cycles: 98.2%
  • Torque retention after 10⁷ cycles: 95.6%
  • No visible loosening or thread damage throughout testing

Comparative testing shows that ordinary Phillips screws maintain only 67% torque retention after 10⁶ vibration cycles, while JIALI PMS-LK series demonstrates superior anti-vibration performance.

4. DJI M300 Field Test Case

In December 2025, ZHUHAI JIALI HARDWARE CO., LTD. collaborated with DJI for field validation on M300 RTK industrial drone flight control boards:

• Application Scenarios: Power line inspection, aerial surveying and mapping, emergency rescue, and other high-vibration conditions
• Installation Quantity: 50 M300 units, each flight control board using 12 PMS-LK M2.5×5 screws
• Cumulative Flight Hours: Over 8000 hours
• Maintenance Records: Zero failures caused by screw loosening, zero re-tightening required

DJI engineers reported: JIALI