The widespread application of diffusion bonding has been hindered, in part, by concerns over kissing bonds. Kissing bonds are generally considered to be conditions where a bond has little or no strength and the concern is that such conditions might escape detection. At Rohr we differentiate between an intimate contact disbond (which has no bond between the surfaces but is detectable by careful ultrasonic testing) and a kissing bond (which also has no bond between the surfaces but is not detectable using current ultrasonic technology). These definitions will be used throughout.