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Many manufacturing projects now require parts with very tight tolerances. Thus it is crucial to choose the right manufacturing technique that will produce the desired results. Precision grinding is one of these techniques. It is an effective machining process for finishing and completing metal parts with tight tolerances.
Precision grinding services create a workable solution for tight tolerances and finishing problems that most metal and non-metal manufacturers face. It provides manufacturers with a higher possibility of producing parts without compromising their quality.
This article will discuss the various types of precision grinding services, their benefits, and applications.
What is Precision Grinding?
Precision grinding is a machining process that involves a specialist spinning consisting of abrasive particles. These abrasives aid in the removal of some materials from a workpiece being worked on. The re-surfacing process will depend on the specification requirements of specific products.
Precision grinding works well with various materials, including minerals, ceramics, and metal. This process is your way to go when other machining methods fail to give the desired precise surfaces and dimensions. It is typically one of the final processes when manufacturing a part.
Types of Precision Grinding
A number of techniques fall under this precision machining category. These techniques are utilized for different components to achieve unique results. Your choice will depend on factors like shape, size, features, and preferred output rate that can influence your choice of a grinder or grinding process.
Here are the types of precision grinding available:
Cylindrical Grinding
Cylindrical Precision Grinding, otherwise known as Center-type grinding, uses a cylindrical grinder to refinish or readjust the surface of a workpiece in a circular form. The workpiece is placed in the mid-point of the machine while a drive dog, drive claw, or center driver rotates it. Different motors rotate the grinding wheel and the workpiece at different speeds.
The cylindrical grinders consist of:
- a grinding wheel
- a grinding claw
- two center holders that hold onto the workpiece
- a chuck or other tool for driving the workpiece
The workpiece and the grinding wheel rotate at different angles; they are parallel in the longitude and radial directions to remove chips. Many cylindrical grinders possess a table that aids the formation of tapered parts. You can control cylindrical grinders using Computer Numerical Control (CNC) or the manual method.
Surface Grinding
Surface grinding is a perfect way of reshaping and refinishing the outer layer of a material to a desirably smooth and flat surface. Here, the abrasive grinding wheel is located at the top, and it spins while the workpiece is tightened to the chuck.
The magnetic chuck in the grinding machine can be of two types – a permanent magnet and an electronic magnet. For a permanent magnet, the chuck possesses an active magnet that attracts and holds different magnetic materials. The magnetic element present in the magnet can move in and out from the parts to activate the magnetic force.
Meanwhile, the electronic magnet or electromagnetic chuck holds workpieces electrically when activated or turned on. A magnetic particle inspection helps to identify any abnormalities or cracks on the surface of the material involved.
Jig Grinding
Jig grinding is very different from cylindrical and surface precision grinding. This is because it produces workpieces with more complex shapes and qualities. One of the visible distinctive features of Jig grinding is a milling machine.
The grinding wheel is retained in a spindle and rotates in the same way as the milling machine does. The spindle involved in this process has a high-speed capability. Therefore, when the spindle is paired with a grinding wheel, the jig grinder can make slots, holes, and inside geometries with high accuracy levels.
Also, Jig grinding creates quality surface finishes compared to traditional milling techniques.
Creep Feed Grinding
This process involves the use of unique or sophisticated grinding equipment. The creep feed grinding wheel works at a prolonged rate to avoid error and increase precision. It produces complex forms or slots in materials that are naturally difficult to grind. These materials include high-temperature nickel-based aerospace alloys and pre-hardened tool metals.
A creep feed grinder has a distinct feature that gives it an edge over other methods. It can work on materials that are highly difficult or expensive to shape. Also, it allows you to change the form of the grinding wheel to facilitate easy and fast design changes.
Single and Double-Disc Grinding
This type of precision grinding uses a large wheel to create flat, parallel workpieces for many productions. Double disc grinders are machines with two unconnected grinding wheels. Parts pass through the faces of these two independent grinding wheels during operation.
Single-disc grinders are not as common as double-disc grinders. These single-disc machines usually have their wheels fastened to a vertical spindle before the operation begins.
Centerless Grinding
Centerless grinding is used to work on parts without places to hold the parts or centers. It works on the outer diameter of bars and tubes. As the name implies, it works without having the workpiece held in a position. Rather, the centerless grinder moves through a control wheel and grinding wheel at a fixed location. This allows it to work on very long bars and tubes.
Internal Grinding
Internal grinding or inner diameter (ID) grinding is used to grind the inner diameter of holes in parts. It uses a tiny high-speed grinding wheel to work on tubular or cannular parts. The high speed applied helps to keep up the proper surface speed. A chuck or collet holds the workpieces in position during the operation.
External Grinding
External grinding, also called outer diameter (OD) grinding, is a process used to work the outer diameter of curved parts. The operations are done between the centers in part. The workpiece and the grinding wheel spin in the same direction. This makes sure the grinding wheel and the surface of the workpiece rotate in opposing directions.
Superabrasive Grinding
This technique uses grinding machines built with hard materials such as borazon, diamond, and cubic boron nitride (CBN). A super abrasive machine can work in place of two or multiple standard methods. This is because it permits closer tolerance machining and reduces tool wear. Ultimately, the process results in total cost savings and superior quality machining.
Thread Grinding
This metal removal process is done with single-point formed wheels or contact. It is commonly used to work lead screws, worms, and ball screws.
Which Parts Need Precision Grinding Services?
Generally, small parts with tight tolerances mostly require precision grinding. However, this process can also work on some large components.
Manufacturers use this process to produce medical equipment, aerospace instruments, tools with blades, and other commonly used components in various industries. These materials need a high degree of parallelism, reliability, flatness, or quality finish.
The parts machined using the precision grinding process are very sensitive, and the level of error is very low. Therefore, every operation requires overall perfection. Having practiced precision grinding over the years, our experience and expertise allow us to successfully handle all your projects.
Benefits of Precision Grinding Services
Precision grinding allows you to achieve a quality and precise finish on parts. Many manufacturers use this technique to produce the most complex and demanding finish specifications on ferrous and non-ferrous metals.
Precision grinding works for a wide array of products with different sizes due to its ability to adapt to specific individual requirements or specifications. Accuracy is crucial for industries with little margin of error, such as automotive, aerospace, medical, and scientific industries.
Therefore, precision grinding is the best next-generation machining technique to opt for. This process is cost-effective and produces better results than many other alternative grinding technologies.
Applications of Grinding Services
Precision grinding applications often demand high-level accuracy and material finish specifications than many other conventional processes or technologies offer. All applications that require profile tolerance or tight flatness are the best fit for this process. Here are some of the common ones:
- Micro-finishing of surfaces
- OD grinding of bearing surfaces
- Machining of pinholes of slots for stamping dies
- Grinding of bearing surfaces
Conclusion
Precision grinding is one of the most effective techniques for finishing parts with tight tolerance requirements. Its benefits include accuracy, cost-effectiveness, increased productivity, and easy quality control.
At AT-Machining, our commitment lies in providing quality service to your company. Our experience with precision grinding technologies and quality management systems will ensure that you get the best results for your project. We are committed to following regulatory requirements so that your parts will meet industry standards.
Contact us today for the most reliable precision grinding services.
