Types and Knowledge of Grinding Machines

How did metal form into a certain shape? How to make them look ‘shiny’? There are many metal processing methods; the most common one is called “Grinding”. It is a precision processing method that uses an abrasive wheel to remove material from the workpiece. It is used for high-accuracy surface, dimension, and shape.

What is a Grinding Machine?

The grinding machine, or grinder for short, is a machine that “grinds” the workpiece. 

The working principle of the grinding machine is similar to holding the sandpaper (abrasive material) to polish the metal board; just the abrasive material is in the form of a circular wheel called a grinding wheel. The grinding machine can not only polish but also cut the workpiece with high accuracy.

How abrasive particles in a grinding wheel remove material from a workpiece.

Photo Source:  Jahobr, Public domain, via Wikimedia Commons

Depending on the material and shapes of the workpiece, there are various grinding machines.

Types of Grinding Machines

1. Surface Grinding Machine

It is the most common type of grinder. It works with a chuck to hold the workpiece fed toward the grinding wheel on the table. It makes the surface of the workpiece flat or smooth.  

2. Double-Column Surface Grinding Machine

It is a kind of surface grinding machine designed for wide and huge workpieces, such as die-mold, the aerospace industry, and the shipbuilding industry. 

3. Cylindrical Grinding Machine

It is a grinding machine designed for the cylinder-shaped workpiece, such as a crankshaft, rod, spindle, motor rotor…etc. The plunge type cylindrical grinder is the best-selling product of Supertec and thousands of units have been sold worldwide.

4. Centerless Grinding Machine

The workpiece of the centerless grinder is not holden by a chuck or spindle, it rests on a blade between two rotating wheels – one is a grinding wheel (moving wheel) for cutting the material, and the other one is called a regular wheel (stationary wheel) which balance the force and direction of rotation movement. Centerless grinding machine is widely used for the mass production of the long and cylinder-shaped workpiece.

Photo Source: Wikipedia - Wizard191 (CC 3.0)

5. Internal Grinding Machine

While the cylindrical grinding machine grinds the outside of the workpiece, the internal grinding machine is used to grind the center hole of the workpiece.

Application of Grinding

• Automotive industry: crankshaft, ejector pin sleeve, spindle motor
• Gear shafts, gears, pumps, connecting rods, and steering pistons.
• Aerospace Industry
• Die and mold 
• Tooling: pistons, roller bearings, spindles, and ball screws.
• Medical industry
• IT industry: Wafer, PCB, smartphone case, tablet case
• Photonics Industries

Advantages and Disadvantages of CNC Grinding Machine

Advantages

1. High Accuracy and dimension: Shape materials in 0.01～0.1μm
2. Processing hard materials
3. Finishing surface
4. Mass and Non-stop Production 

Disadvantages

1. It can remove only a small amount of material, if you want to remove a large amount, you need to use other kinds of CNC machine.
2. Higher cost than other kinds of CNC machine
3. Personnel training: The experience of controlling temperature, RPM and choosing right abrasive need long time to train. 

Conclusion

Taken together, a lot of products in our daily life are processed by grinding machines. Its ability to finish surfaces with high accuracy is non-comparable with other processing methods. A grinding machine is the best choice when comes to fine finishing and accurate dimension.

As one of the leading CNC grinding machine manufacturers in Taiwan, Supertec is committed to offer excellent service and products. Looking for grinding solutions? Feel free to contact us!