Author: Haroon Khalil

Up Milling and Down Milling: The horizontal milling is divided into two groups: up milling and down milling. If the direction of cutting and feed are opposite to each other, the milling is known as up milling, and if the direction of both are same, the milling is known as down milling as shown in Figure 19.42.…

Base: The base is foundation part of a milling machine. It is made of grey cast iron. It absorbs vibrations and supports column, table arbour, etc. Column: It is main casing mounted on one side of the base. This is box shaped and fitted with gearing arrangement for different spindle speeds and table feeds (Figure 19.41). Knee: It…

Milling is a metal cutting process in which different shapes and sizes of the surface are generated by cutting action of rotating multi-point cutter fixed on a periphery of a wheel and feed is given to the work. The shaft on which milling cutter is mounted is known as arbour, this may be horizontal or…

Main specification of a boring machine is designated by the following terms:

Boring machine is one of the versatile machine tools. This is most suitable for machining of large and heavy workpiece in mass production, for example, cylinder of IC engines, machine housing, engine frame, etc. This machine can perform all the operations which can be done on drilling machine. But this machine is heavier than the…

Radial drilling machine is a heavy duty machine. It consists of a vertical column supporting a horizontal arm on which drill spindle can move in radial direction. The arm can be raised or lowered and swung around any position over the work. Two electric motors are used as shown in Figure 19.38, one used to provide movement…

Drilling: The operation of producing a circular hole by removing metal by rotating the cutting edges of a drill is known as drilling. Metal is removed by shearing and extrusion (Figure 19.31). Drilled hole is slightly oversized due to non-alignment of the tool and vibration of the spindle. For producing accurate hole, the drill bit selected…

Drilling machines are specified in the following ways:

Rake Angle: It is also known as helix angle. The angle between a plane passing through drill axis and leading edge of the land is known as rake or helix angle. It varies from 0° to 48°. Higher values are suitable for softer materials and lower values are suitable for harder materials. Point Angle: It is also…