Which material can screws and bolts securing water closets to the floor plane be made of?

The material that screws and bolts securing water closets to the floor plane can be made of is brass. Brass is favored in plumbing applications because it is resistant to corrosion and has good tensile strength, making it durable enough to handle the stress and weight of fixtures like water closets. This resistance to corrosion is particularly important in a wet environment, helping to ensure a long service life without the risk of rust or degradation, which would compromise the joint's integrity.

While other materials like stainless steel and galvanized steel are also commonly used in the plumbing industry, brass is often preferred for its combination of strength, weight, and resistance to rusting. Plastic, although lightweight and resistant to corrosion, does not offer the same strength and durability as brass for securely fastening heavy fixtures. Therefore, brass is the most suitable choice for this specific application.