This book on ?Basics of Surface Technology? has been written mainly for the undergraduate students of Metallurgical and Materials Engineering, and Mechanical, Production and Maintenance Engineering in Technical universities. Many structural components and engineering machine parts lose their function and fail due to surface degradation causing shut down of the plant involving monetary loss and man hours. It is very essential to maintain the parts of the structure and machines in proper condition so that continuous production can be ensured. The engineering students should have a thorough knowledge of surface engineering and technology so that they can take preventive measures to stop or minimize the break down of the engineering components.As in many structural and production machineries iron base alloys and nickel base super alloys are used, the metallurgical background of these materials is described in the second chapter. The basics of surface degradation like wear, erosion, corrosion, oxidation, and hot corrosion are explained in the next chapter. Surface treatments to withstand aggressive environments are given in the following chapters dealing with diffusional and non-diffusional processes.Surface coatings based on chemical and electro-chemical depositions, welding and cladding are presented and discussed in detail. Advanced methods of surface treatment by thermal spraying, physical vapour deposition and chemical vapour deposition for high technological applications are explained with suitable illustrations for basic understanding of the process.Testing methods for the quality and soundness of the coated surface and the international standards are given following which the industrial applications of the surface treatment for different requirements are discussed.Finally, for the benefit of undergraduate and postgraduate students, a chapter on questions has been added which will be very useful to have a thorough understanding of the subject and solve any practical problems in surface technology.