Impacts of oblique detonations in pentolite on iron are treated by the methods of plane, steady, compressible flow. Regular reflection, three-shock Mach reflection, and expansion are discussed. The maximum transmitted pressure, 452 kbar, is shown to occur at an impact angle of 63.4°, at the onset of Mach reflection. The steady double plastic wave structure in iron, which appears at impact angles between 71.3° and 90°, is calculated. Results for two colliding detonation waves are obtained as a special case.