Precautions for Grade 12.9 DIN 916 Hexagon Socket Cup‑Point Set Screws

1. Installation must strictly follow the recommended tightening torque in the above table. Over‑torque tightening is strictly prohibited, as it will directly cause screw fracture or thread stripping. Insufficient torque will result in locking failure and component loosening.

2. Tightening by hand feel is forbidden. Torque wrenches must be used, especially for large sizes above M6. A torque deviation exceeding 20% will lead to failure.

3. The torque‑bearing capacity of screws decreases after repeated disassembly and assembly. For critical safety applications, one‑time use or replacement with new screws each time is recommended.

4. Grade 12.9 is high‑strength steel. Hydrogen embrittlement relief treatment is mandatory after electro‑galvanizing. Untreated products are strictly prohibited for use, as they may suffer unpredictable hydrogen‑induced delayed fracture during service.