Internal torx star-shaped slot drive head
The center of the head is equipped with a six-lobed star-shaped internal梅花 slot (Torx Plus). Compared to the traditional internal hexagon， the contact area increases by 30%， the torque transmission efficiency is higher， and it is less prone to slip； the star-shaped structure requires the use of a special wrench and has basic anti-theft functions. The head is laser marked with "A2-70" material grade and specification identification， facilitating quality traceability.
Integrated flower teeth anti-loosening washer
At the transition between the head and the shaft body， there is an integrally formed radial flower teeth (Knurling Washer) with sharp teeth at a 60° angle. When tightened， it embeds into the metal or hard plastic surface， forming a microscopic mechanical interlock， preventing the screw thread pair from relative rotation under vibration conditions， and its anti-loosening performance exceeds that of ordinary spring washers.
Fine tooth precision thread section
Designed with fine tooth threads， the pitch is small and the thread helix angle is low， resulting in excellent self-locking performance； the thread accuracy is grade 6g， with a surface roughness of Ra ≤ 1.6 micrometers， ensuring smooth cooperation with the nut and a small pre-tightening force dispersion.
Cylindrical guiding positioning section
At the end of the thread， there is a precision smooth rod section without threads， with a diameter slightly smaller than the thread minor diameter， which can be used as an introduction and alignment axis during assembly to ensure the coaxiality of the bolt and the hole； the smooth rod section can also withstand lateral shear force， preventing the thread from being sheared and damaged. 
Stainless steel A2-70 material
304 austenitic stainless steel， after cold hardening， reaches a strength of 70 grade (700 MPa tensile strength)， has excellent corrosion resistance and high load-bearing capacity， is non-magnetic， and is suitable for electromagnetic-sensitive environments.

Triple guarantee for anti-loosening performance
The low rise angle of fine-threaded screws self-locks, the mechanical interlock of the flower-shaped gasket, and the high friction coefficient of stainless steel material form a triple anti-loosening mechanism. Even in strong vibration scenarios such as in rail transportation, the pre-tightening force remains undiminished, and the probability of loosening is reduced by over 90%.
Efficient and reliable torque transmission
The internal torx groove and the six-point contact of the wrench evenly distribute the stress， avoiding the problem of edge collapse that is prone to occur in internal hexagons. It allows for the application of higher tightening torque， resulting in a tighter connection and an extended lifespan of the wrench.
Precise and fast guiding assembly
The end light rod segment is pre-imported into the hole and automatically corrects the deviation of the hole position. It can be quickly inserted without visual alignment， increasing the assembly efficiency by 40% and being particularly suitable for automated production lines or blind assembly scenarios.
Long-lasting and maintenance-free corrosion resistance
The 304 stainless steel body is corrosion-resistant and does not require galvanization or painting. There is no risk of corrosion after the coating is scratched. It can achieve full-life cycle maintenance-free in outdoor， coastal， and chemical environments.
Exquisite appearance without protrusion
The cylindrical head is combined with the flower-shaped gasket， and after tightening， the head is flush with or slightly lower than the surface， without exposed protrusions. It is both beautiful and safe， and will not scratch people or get tangled with foreign objects like external hexagon bolts.

Rail transit vehicles
The interior panels, seat frames, and electrical cabinets of high-speed rail and subway carriages meet the EN 12663 vibration standard. The serrated anti-loosening ensures no loosening during high-speed operation, and the internal梅花 design prevents passengers from randomly disassembling.
New energy battery system
The shell fixation of lithium battery modules and battery packs， and the connection of current collectors， have no magnetic stainless steel that interferes with the magnetic field detection of the cell management system. The A2-70 strength meets the structural safety requirements.
Medical equipment
The precise adjustment mechanisms of surgical beds， imaging equipment， and rehabilitation devices. The dull surface has good biocompatibility and can withstand high-temperature and high-pressure sterilization. Fine-threaded screws achieve micro-adjustment accuracy.
Electronic communication chassis
The electromagnetic shielding covers for 5G base stations and server cabinets are fixed without magnetic materials that interfere with signal transmission. The serrated gasket ensures continuous grounding， and the internal torx design prevents unauthorized opening.
Outdoor public facilities
The shell fixation of smart lamp poles， surveillance cameras， and charging stations. Stainless steel is weather-resistant and requires no maintenance. Anti-theft slot-type reduces vandalism. The guide column facilitates quick assembly from a height.
Food and pharmaceutical machinery
The sanitary fastening of filling equipment and mixing tanks. The surface has no risk of coating detachment. It complies with FDA and GMP standards. The serrated anti-loosening is suitable for the vibration environment of CIP cleaning.