I would like to take this opportunity to express my sincere and deep sense of gratitude to my guide, Prof. S. B. Belkar, for their timely guidance and inspiration, who answered all my queries and advised with comments for the collection of literature, proper structure of experiments and improvements without which my work would not have been completed. I would also like to thank him to giving me this opportunity to study the vast and interesting field of welding strength. I also wish to express my sincere thanks to Principal, Amrutvahini College of Engineering, Sangamner-422605, Dist.-Ahemednagar, Maharashtra, India. HOD and Vice-Principal Prof. A. K. Mishra for their valuable and motivating support throughout the course of the book.Department of Mechanical Engineering and all supporting Professor. Who helped and support me for writing this book. My Parents Mr. Keshavrao Dighe and Mrs. Pushpalata Dighe are my role model and who always support m