© 2018 Trans Tech Publications, Switzerland. Impact joining device was developed to achieve the joining at plate edge. The sheared faces obtained by high-speed shear are availed in the joining method. The temperature remarkably elevates and the material softens in the thin severely deformed layer. The cut faces are contacted each other with sliding motion immediately after shearing process. Slight overlap for the opposed cut faces is set. In the similar material combination of mild steel (SPC), the effect of overlap length on the average joining efficiency was not clear. The data spread became smaller for the shorter overlap length. Microscopic observation discovered that there is a narrow band where the grain flow was not visible due to the remarkable temperature rise. In the dissimilar material combination of titanium (TP340C) and SPC, generation of a certain metallic compound was implied by energy dispersive X-ray analysis.