Six Sigma is the concept of improving the quality by reducing process variations, making con-tinuous improvements, reducing defect rates and improving the processes. Initially, the concept of Six Sigma focused on defect reduction, cost reduction and value addition. Fundamentally the basic idea of Six Sigma is to improve the process-capability and making the process more relia-ble along with reducing wastes within industries. Evaluation the implication of applying Six Sigma over the small and medium-sized enterprises is the main purpose of this research work taking a particular case of automobile industries. In the present work, DMAIC methodology of Six Sigma is used to a small seat slider lock nut manufacturing unit to reduce the play issue in K2 seat slider lock in automobile units by reducing defects inherent in the process. After apply-ing Six Sigma methodology, it was found that manufacturing units could earn profits in terms of reducing the wastage as well as improving the quality standard of the product by controlling the play issue in seat slider lock nut mechanism. Result shows that with the application of Six Sig-ma, process, sigma level brought up to 5.53σ from 1.59σ by varying the seat slider lock nut di-mensions/size.