Final answer:
Technicians can determine the grade of a bolt by examining its markings.
Step-by-step explanation:
Technicians can determine the grade of a bolt by examining its markings. Grade markings on bolts typically consist of numbers or letters that indicate the strength and material composition of the bolt. For example, grade 5 bolts are made of medium carbon steel and are commonly used in automotive applications, while grade 8 bolts are made of alloy steel and are used in high-strength applications.