Deep drawing process is one of the most important and sophisticated sheet metal forming process. It involves not only bending but also stretching, thinning, thickening, pulling, tension and compression of metal over wide area simultaneously. Deep drawing process may cause many defects such as wrinkles, orange peel, earing, tear, draw marks, burnishing and etc. The defects occur because of many factors such as punch force, blank holder force, material properties, drawing rate, drawing speed, punch die clearance, die corner radius, punch corner radius, drawing lubricants and etc. The purpose of this project is to determine the cause of the defects which occur when producing deep drawing car component, the bracket fuel filler neck at PROTON. In Proton, defects such as wrinkles, fracture (tear) and drawn marks occur during the deep drawing process. This study focuses on the properties of the materials such as microstructure, work hardening during cold working, yield strength, tensile strength, maximum elongation, drawability and hardness. Several testshave been carried out to determine these properties such as tensile test, cupping test and hardness test. Discussion of the testing results is finally carried out to determine the cause of the defects. The results illustrates that the yield strength (206,67Mpa), tensile strength (127.92Mpa) and maximum elongation (35.54%) are not according to the specification while the other results illustrate that the material have a high rate of deep drawability and stretch formability. This shows that the material which has been tested and studied, can be successfully perform under deep drawing process without fracture. The tear defect which occur in random may due to the particular coil of sheet metal is out of the specification.