Selecting fasteners requires a comprehensive evaluation of several factors. First is the type of load associated with the application: static loads (such as in structural anchoring) can be accommodated by standard carbon steel bolts, whereas dynamic loads (such as those involving mechanical vibration) require high-strength alloy steel combined with anti-loosening measures (e.g., spring washers).
Second is environmental compatibility: chemical processing equipment requires acid- and alkali-resistant Hastelloy fasteners, while outdoor installations necessitate consideration of salt spray resistance ratings. Additionally, installation efficiency is a critical factor; self-tapping screws are suitable for rapid assembly, whereas high-precision bolts require specific installation clearances.
For instance, insufficient bolt preload can lead to connection loosening, while excessive preload may trigger hydrogen embrittlement failure. Consequently, industry best practices recommend using torque wrenches to control installation torque and conducting periodic ultrasonic or magnetic particle testing to identify potential issues. For critical structures, Finite Element Analysis (FEA) should also be employed to simulate fastener stress distribution and optimize design parameters.
Appearance requirements: The fastener color should match the connected components; in the absence of specific requirements, a standard silver-white finish is generally acceptable.
Rust prevention requirements: Surface treatments should be selected based on the corrosivity of the operating environment; for humid or coastal environments, priority should be given to treatments with superior corrosion resistance, such as galvanizing or Dacromet coating.