In this paper the dynamic fragmentation behavior of a metal disc, positioned at the interface between colliding detonation wave fronts, is investigated. Flash x-ray radiography images from both 150kV and 450kV sytems were obtained to study the break-up phenomena of the metal disc between two similar explosive charges initiated simultaneously. The study was limited to discs of oxygen free high purity copper and an aluminium alloy (6061 T6). During the inititial shock loading phase the disc is stretched accompanied by the formation of spalling fragment rings. At a later stage discrete fragment rings are formed, which fly outward in an expanding disc fashion. The measured discrete fragment velocities ranged between 0.19 mm/μs and 2.7 mm/μs, depending on the material type. Flash x-ray radiography data at specific times is compared with numerical simulations performed using 3D-AutodynTM. Experimental techniques, procedures and results will be presented for the different metals.