P PT. Karya Adikita Galvanize is a manufacturer of electrical components. The research was conducted from July 2020 to August 2020 in the injection section where the Service Wedge Clamp 2x4-16 mm product was manufactured, found the number of product defects. Therefore, this research objective is to improve the quality of the Service Wedge Clamp 2x4-16 mm. This study uses the Six Sigma method. At the define stage, it identifies with Supplier, Input, Process, Output, and Customer diagrams and Critical to Quality on the characteristics of the types of defects, namely short shot, flash and imprecise holes. Then, in the measure stage it uses the P control chart with the calculation of the value of Defect Per Million Opportunities of 38069.22 and a sigma level of 3.2735. In the Analyze stage it is performed by determining the dominant cause of the Risk Priority Number value calculation. From the aboves, it is obtained the cause of overheating with a value of 336, machine setup is less than optimal by 280, and there is foreign material of 200. The stage of improving determination of the proposal with 5W + 1H questions and Design of Experiments. For the cause of overheating, make a form for checking engine parts, it is using a closed container and metal detactor for the cause of foreign material, and using the Design of Experiments method for the causes of machine setup settings. After carrying out the implementation by making a form and using a container (tong), the Defect Per Million Opportunities value was obtained at 22787.88 and a sigma level of 3.4993.