In a recent discussion on Great Question: A Manufacturing Podcast, attention was drawn to a crucial but often overlooked detail in industrial quality control: the distinction between a part being "capable of" and a part being "tested to" a specific standard. The episode, featuring New Equipment Digest’s Editor-in-Chief, Laura Davis, focused on the widely used ultrasonic testing standard, ASTM A388, and its role in ensuring the integrity of metal components.
The conversation highlighted that while a manufacturer may claim a part is "capable of ASTM A388," this phrase does not guarantee that the part has undergone the actual ultrasonic inspection. Instead, it merely suggests the manufacturer's belief that the component could pass the test if performed. For critical applications in aerospace, energy, and heavy industry, this theoretical assurance is not sufficient. Invisible flaws within the metal, such as voids or cracks, can become serious weak points under high stress or extreme temperatures, leading to potential catastrophic failure.
To counter this risk, Original Equipment Manufacturers (OEMs) are increasingly mandating documented proof that ultrasonic testing has been performed on parts, ensuring a higher level of safety and reliability. The discussion explained that ultrasonic testing is a non-destructive method that uses high-frequency sound waves to find internal flaws.
The report also detailed the practical challenges and requirements of the testing process. Forgings, often delivered in a rough "as forged" condition, require proper surface preparation before they can be inspected. The outer, irregular layer must be machined away to eliminate a weak zone and achieve a smooth surface finish of at least 250 RMS. This precise preparation is essential to prevent sound waves from scattering, which could weaken the signal and cause internal flaws to be missed.
The podcast episode, based on an article by technical writer Del Williams on behalf of All Metals & Forge, LLC., serves as a practical guide for those involved in quality control and engineering who need to understand the importance of proven and documented testing. The conversation underscores that in applications where safety and precision are paramount, "capable of" cannot replace "tested to."
