Which of the following is NOT a type of stay?

The type of stay that is not recognized in standard engineering terminology is the vertical stay. Stays function as structural supports typically found in various applications like bridges, scaffolding, and boilers. Stay bolts, diagonal stays, and gusset stays are all well-defined categories.

Stay bolts are commonly used in boilers to secure the structure and maintain integrity against internal pressure. Diagonal stays provide support by bracing structures at an angle, enhancing stability and reducing the risk of swaying or buckling. Gusset stays utilize triangular plates to strengthen joints and connections, providing additional reinforcement in a construction context.

In contrast, a vertical stay is not a standard term associated with the common types of stays in engineering. While vertical supports exist in various forms, they do not specifically fall under the classification of stays, making it clear that this term does not properly align with the established categories of structural supports.