i-Bolt Technology equips each fastener with a proprietary low-cost, permanent ultrasonic transducer at the top, bottom, or both ends of the bolt. Load measurements are made via the pulse echo technique to 3σ accuracy better than ±3%. Each instrumented bolt is also equipped with the i-Bolt patented transducer-embedded 2D-barcode. Every fastener is fully traceable and includes a database and automatic data logging. There is no special fastener preparation, no acoustic coupling problems, and no highly-trained technician requirements as is the case for removable ultrasonic solutions.