ABSTRACT
Drilling is the most commonly used machining operation; it finds widespread applications in machine-shop practice and in fields such as ship building, oil & gas exploration, etc. This chapter first introduces readers to drilling and its industrial applications, and then drilling-related operations (drilling, tapping, reaming, boring, counter-boring, counter-sinking, etc.) are discussed. The drill bit is specifically explained with reference to its materials and its types; here the geometric design parameters of twist drill bits are also discussed. Besides explaining the basic function of a drilling machines, major types of drilling machines have been illustrated with the aid of diagrams/labeled photograph; these machines include upright drill press, radial arm drill press, multiple-spindle drilling machine, gang drilling machine, turret drill press, and the like. The drilling operation has been mathematically modeled so as to enable us to calculate the spindle rpm, feed rate, cutting time, material removal rate (MRR), chip area per unit lip, cutting force, thrust force, cutting torque, and the cutting power. This chapter contains 14 calculations/worked examples and 6 MCQs.
