What does it indicate if a bolt is classified as 'high strength'?

A bolt classified as 'high strength' indicates that it possesses a higher tensile strength and an enhanced ability to withstand loads compared to standard bolts. This classification is crucial in applications where the bolt must endure significant forces or stresses without failing. High strength bolts are typically made from stronger materials and undergo specific heat treatment processes to ensure their performance, making them suitable for demanding structural applications like bridges, buildings, and machinery where safety and reliability are paramount.

The other options do not align with the characteristics of high-strength bolts; for instance, a lower yield strength would not contribute to the bolt's ability to endure high loads, and flexibility is not a desirable trait for bolts intended to secure structures. Additionally, while aesthetic aspects can be considered in certain designs, the primary purpose of high-strength bolts is functionality and performance, not appearance.