What are aircraft bolts with a cross or asterisk marked on the bolt head typically categorized as?

Aircraft bolts that feature a cross or asterisk mark on the bolt head are specifically categorized as high-strength bolts. The marking indicates that these bolts are designed to endure high loads and stresses, which is particularly important in aviation applications where safety and structural integrity are paramount.

High-strength bolts are typically made from materials that have undergone specific heat treatments and processing to enhance their tensile strength, making them suitable for demanding environments such as those found in aircraft.

Other options pertain to different types of bolts with unique characteristics. For instance, aluminum bolts are lightweight and corrosion-resistant but do not possess the same strength characteristics as high-strength bolts. Standard steel bolts may be used in general applications but do not provide the critical load-bearing capabilities required in aerospace. Corrosion-resistant bolts are engineered to withstand environmental factors but are not exclusively classified by the strength characteristics associated with high-strength bolts.

Thus, the presence of a cross or asterisk marking on the bolt head signifies its classification as a high-strength bolt, affirming its suitability for aviation demands.