Standard ultrasonic calibration step block: Metric design for calibrating thickness gauge linearity and flaw detector sensitivity. Multi-step thickness layout: Popular models include Metric 5 Made of high-quality carbon steel: A1018 steel ensures stable acoustic velocity and durability for industrial use. Complies with standards: Guarantees accurate calibration results aligned with global NDT protocols. for thickness and linearity checks: Widely used in ultrasonic testing of pipes, plates, and welds.