Welding is an assembling process highly used in industry. Because of current market requirements, manufacturers push welding processes up to their limits: increasing productivity, reducing costs as well as ensuring welding assemblies quality. However, increasing welding speed causes many defects such as hot cracking (also known as hot tearing or solidification cracking). It is one of these defects which strongly affect weld quality and mechanical strength. The aim of this study is to link up the emergence of hot tearing with characteristic length of material by means of different measures.