1. Requirements on mechanical properties, especially strength, of fastener materials.
2. Requirements of working conditions on corrosion resistance of materials.
3. Requirements of working temperature on heat resistance (high temperature, strength and oxidation resistance) of materials.
4. Requirements for material processing performance in terms of production process.
5. Other factors, such as weight, price and procurement, should be considered.
After comprehensive consideration of these five aspects, the brand, variety, specification and material standard of selected fasteners are finally determined.