Black Grade 12.9 DIN 912 Cylindrical Socket Cap Screw/Allen Bolt/Bolt/M3 X 6mm M20 M14 X 2mm

Black Grade 12.9 DIN 912 Cylindrical Socket Cap Screw/Allen Bolt/Bolt/M3 X 6mm M20 M14 X 2mm​
 

Unlike the standardized structures of general-purpose fasteners (such as Phillips screws and hexagonal nuts), the structures of specialty fasteners must be tailored to specific assembly requirements. Common customized structures include:
 

1. Leak-proof structures: such as "sealed bolts" with sealing rings (a rubber/metal sealing ring integrated into the bolt head or threads, used in hydraulic systems and gas equipment to prevent leakage);
2. High-precision positioning structures: such as "stepped positioning screws" (a screw shank with a precise step ensures both tightening and coaxiality between components, suitable for precision instruments such as optical lenses);
3. Anti-loosening and anti-slip structures: such as "serrated lock nuts" (with reverse serrations on the inner wall to prevent loosening due to vibration after assembly, used in automotive chassis and rail transit equipment) and "expansion anchor bolts" (which expand and lock into place after penetrating concrete or metal substrates, suitable for securing building curtain walls and heavy equipment);
4. Integrated functional structures: such as "smart fasteners with sensors" (pressure/temperature sensors embedded in the screws to monitor tightening status in real time, used for health monitoring of large structures such as wind turbines and bridges).

Features:
 

High-temperature resistant materials: Nickel-based superalloys (such as Inconel 718, capable of operating at temperatures above 650°C for extended periods, used in aircraft engines and boiler components); titanium alloys (such as TC4, heat-resistant and lightweight, used in aerospace structures);
Extremely corrosion-resistant materials: Hastelloy C-276 (resistant to strong acids, alkalis, and seawater, used in marine engineering and chemical storage tanks); Monel 400 (resistant to seawater and chloride ion corrosion, used for ship propeller mounting);