What is the difference between a fastener’s size and its grade, and where is each indicated on a bolt?

What is the difference between a fastener’s size and its grade, and where is each indicated on a bolt?

• A. Size refers to diameter and thread pitch; grade indicates strength class; the size is on the threaded part and the head/markings show grade.
• B. Size equals material; grade equals manufacturing process.
• C. Size equals color; grade equals length.
• D. Size equals head type; grade equals coating.

Answer: (B)