Grinding machines are material removal tool used for surficial removal in low rate. They uses abrasives as primary material to remove material. Grinding Machines are extremely useful for matching dimensional tolerance, fitting, surface finish and tool sharpening. Grinding is a finishing operation which utilizes a multi-points randomly oriented abrasives in a form of grinding wheel to remove materials for performing finishing operation.
Manual Grinder are used to grind general tools and materials which does not require much dimensional accuracy. Material is held by a hand or fixture and fed in cylindrical of flat face of the grinding wheel.
Surface grinding machine is used to finish relatively larger flat surfaces mounted over an x-y-table. The grinding wheel mounted on the horizontal shaft is feed towards the workpiece to perform finishing operation. The grinding wheel is characterized by the material, grit size, and type of bond, spacing between the abrasives and bonding material. Grinding operation consumes highest specific power among the commonly used conventional machining operations.
Configurations of a surface grinder
Grinding Capacity : L ×W× H (mm × mm× mm)
Longitudinal table travel (mm)
Cross table travel (mm)
Max. distance from the spindle center to the worktable surface (mm)
Unlike a magnetic fixture or any other fixture in a surface grinder, in centerless grinder there is no such fixture for holding the workpiece. The workpiece, which can be a delicate part not suitable to hold in a fixture or an irregular shape, is hole between the grinding wheel (cutting wheel) and a regulating wheel. Axis of the wheels are not exactly parallel rather there is an angle between two wheels, which provides automatic feed during the cutting operation. Figure below shows a centerless grinding machine.
Configuration of a typical centerless grinding machine
As name suggests these kind of grinders are specifically designed to finish the internal surfaces such as internal holes and bores. The inner surfaces are finished by passing the grinding tool in the rotating workpiece and material removal occurs similar to any grinding operation. Sometime it is possible to use multiple wheels for specific applications. The typical applications of internal grinding include precise finishing of pipes, tubes, bearing races, bushings, etc.
Configuration of a typical internal grinding machine
Max job length (mm)
Max grinding length (mm)
Height of centre (mm)
Internal grinding Spindle
RPM if ID spindle
HP of wheel
Spindle morse taper
No. of speed
HP of motor
0.5/ 1 HP
Total weight (Kg)
Hydraulic infinitive variable speed
Shoe magnetic centre less chucking system/ Diaphragm chucking system/ Three Jaw chuck/ four jaw chuck /Hydraulic collets/ manual collets /hydraulic chuck
Slide ways coated with ‘TURCITE’
Variable speed control AC drive in work head with digital read out
Automatic grinding cycle
Hydraulic size unit in cross slide, spark out, fast retract / CNC, HMI & PLC operated cross slide
DRO in cross slide
Micro feeding attachment
Magnetic separate / paper band filter/ magnetic Separate with paper band filter
These are special purpose grinder machine designed to grind highly eccentric profiles accurately, there design is almost similar to big lathe having grinder wheel & motor arrangement in tool post. It has arrangement of a grinding wheel and tool which have radial and transverse movement to grind and finish complex surface like crank shaft of engine.
Configurations of a typical crankshaft grinding machine
CNC Grinder again digital upgrade of Manual grinders where, job handling, grinder wheel/tools engaging etc. all operation are controlled electrically by a computer onboard. These are advantageous for precision grinding and in complex profiles. Grinding position and material removal are al indicated using computer aided design and data is fed to the CNC Grinder to get the job done automatically.
Configuration of a CNC grinding machine
Centre height (mm)
Admit between centre (mm)
Swiveling range (degrees)
-15 to +225
B- axis resolution (degrees)
Grinding wheel size (OD × thick × bore) left side (mm)
500 × 40 (50 ROS) × 203.2
Grinding wheel size (OD × thick× bore) right side (mm)
Drilling Machines are used to drill precise holes in a workpiece. Prior to drilling, the work is centre punched for indent marking. A drill bit with the requisite diameter is mounted in a check and rotated with an electric motor set to the required speed. To cut a hole in the work piece, the revolving drill bit is lowered using a rack and pinion system. It also has a depth limiter.
Drilling and thread-making machines are specialized machines. Taps are used as a cutting tool and are installed on a chuck with a motor. They can also move in translation. The work piece is drilled for a standard hole in a separate drilling machine, and the threading is completed on this machine or with a combination drill tap tool. When tapping and drilling, it’s crucial to utilize lubrication.