How far should the threads of a bolt be run into the nut for proper engagement?

For proper engagement, a bolt should typically be run into the nut halfway through. This level of engagement ensures that the threads are adequately meshed, providing sufficient grip and load-bearing capacity while avoiding excessive strain on the threads. If the engagement is too shallow, like one-fourth way through, it might lead to insufficient connection strength, increasing the risk of failure under load. Conversely, while fully engaging the threads might seem optimal, it can sometimes lead to complications such as needing too much torque to tighten or difficulty in assembly and disassembly. Thus, halfway through strikes a balance, offering good support and ease of use, ensuring the connection is secure while minimizing the risks of thread stripping or damage.