Today, manufacturing has developed to a more complex setting, requiring tight tolerance for several custom parts or prototypes. Therefore, manufacturers must employ suitable machining techniques to produce components that meet the standard requirements. Precision grinding remains one of the most effective machining processes applied across diverse industries to produce quality parts. Hence, this article examines the various types, working principles, and Carbide Aluminum Inserts applications of precision grinding. Let’s get right into it.

Precision grinding is a form of grinding process that focuses on manufacturing and finishing parts with very close tolerances. Typically, grinding machining constitutes a subset of cutting as a metal-cutting process in manufacturing and tool-making. In production, grinding is used for machining various materials, particularly for making shallow cuts to produce fine finishes, shapes, and dimensions.

However, some industrial manufacturing processes require precision and accuracy, so there is little room for production errors, which applies when aiming to fabricate specific components without compromise. As such, precision grinding provides workable solutions to the issue of tight engineering tolerances and finishing problems that most manufacturers face. This grinding operation can remove materials to produce custom parts with tight tolerance dimensions or quality surface finish.

More specifically, high precision grinding allows the machining of workpieces with complete accuracy, achieving very close tolerances as intricate as +/- 13 microns to +/- 1.3 microns for diameter and +/- 2.5 to 0.25 microns for roundness. Likewise, the method can also attain precision for typical finishes with a tolerance range of 0.20 to 0.81 microns.

Precision grinding offers certain benefits in manufacturing. Check them below:

To a large extent, high precision grinding guarantees accuracy while providing a cost-effective means of producing different parts. Most metal manufacturers use this machining method to reproduce specific measurements of intricate parts within the acceptable level of variance. On top of this, the grinding operation helps increase the manufacturing productivity of exact parts while making quality control consistent and easier. Put together, precision grinding is an efficient manufacturing process.

Expert machinists use precision grinding processes when other machining methods or techniques like milling and turning cannot be used. This usually occurs due to the following:

• Type of material；
• The quality of the surface finish required；
• The need to produce parts with small diameters and tight tolerance.

There are diverse types of precision grinding processes applied to achieve the precise surface finish and dimension for various components. The characteristics of these grinding operations inform their respective application for specific machining projects. As a result, manufacturers must select the proper grinding operation depending on the size, shape, finishing features, and desired production rate needed for the part.

Here are some of the commonest types of precision grinding.

Surface grinding is a machining process that produces a smooth finish on flat surfaces, giving them a more refined appearance or adding a particular function. It involves using a rotary wheel coated with rough abrasive particles to remove tiny chips or excess material from the surface of the workpiece. Aside from the wheel, the surface grinding machine comprises a chuck and a table that uses magnets to affix the material.

The integration of CNC provides automated features that enable the consistent removal of materials, thus ensuring high-volume production. However, most precision surface grinding processes are often applied to make the two ends of a metal part perpendicular to the external diameter. In other cases, it is used to attain parallel or squareness in cubic parts.

When CNC turning and milling processes are not adequately precise for a manufacturing project, manufacturers employ precision surface grinding as an excellent alternative. This is because the grinding operation can attain micron-level production tolerances and finishes as low as 0.2 microns. Note that the quality of surface finishes obtained with surface grinding depends on factors such as wheel speed, feed rate, wheel size, abrasive material, and the type of material.

Additionally, surface grinding is well suited for materials easily held by the magnetic chuck without clogging the grinding wheel. These materials include cast iron and many steel grades. Other materials like aluminum, brass, and plastics clog the wheel, preventing it from cutting. That way, only expert machinists conduct surface grinding operations for these materials.

This grinding operation, also known as center-type grinding, applies to cylindrical surfaces and the shoulder of suitable workpieces. A cylindrical grinder comprises a grinding wheel, a chuck, two centers that hold the workpiece in place, and other features for driving the workpiece. Furthermore, most cylinder grinders come with a swivel to create tapered pieces. The abrasive or grinding wheel can also have different shapes. Machinists use the standard disk-shaped wheels to fabricate tapered or straight workpieces, while the formed wheels help create shaped workpieces.

Concisely, the workpiece is affixed on the center and rotated by the lathe dog or center drive in cylindrical grinding operations. The workpiece and the grinding wheel use separate rotary motors at different speeds. More so, the wheel and workpiece move parallel to one another in longitudinal and radial directions.

Generally, precision cylindrical grinding provides smooth surface finishes for round objects. Moreover, the standard precision tolerances for cylindrical grinding stands at 1.3 microns for diameter and 0.25 microns for roundness. There are two main types of cylindrical grinding, which are:

Internal or Inner Diameter Grinding

As the name suggests, this cylindrical grinding type removes excess material on the internal diameter (ID) of tubes or other part features, including holes or bores. Manufacturers use ID grinding alongside honing to produce smooth surface finishes and parts with tight tolerances.

Both ID grinding and honing processes involve holding the workpiece in place and rotating to limit the size of the part’s internal diameter, becoming lesser than the grinding wheel diameter.

External or Outer Diameter Grinding (OD)

Outside diameter (OD) grinding uses a single wheel to shape the external surface of the workpiece held by the centers. During the OD grinding process, both the grinding wheel and the workpiece rotate in the same course around the central axis constantly. While OD grinding applies to various part shapes such as cylinders, ellipses, and cams, note that the workpiece must have a sizeable central axis diameter that allows hitch-free rotation.

This grinding operation entails removing tiny materials to produce a specific finish to the outside diameter or periphery of small, cylindrical workpieces. In most cases, manufacturers use centerless grinding to enhance the surface finishing of turned machined parts to achieve more precision. In contrast to traditional OD grinding machining, centerless grinding does not hold the workpiece between centers or chucks. Instead, the centerless grinder uses a rest blade to support the workpiece on the outside diameter.

Further, centerless grinding employs the action of two wheels: the abrasive grinding wheel and the regulating wheel. Even though both wheels rotate in the same direction, the grinding wheel rotates at a higher speed than the regulating wheel. This allows the centerless grinding operation to grind very small parts.

Unlike other grinding processes, the workpiece moves through the centerless grinder machine without fixtures or motors. Instead, the grinding operation controls the movement through the so-called “magical angle” between the two wheels.

In most manufacturing industries, precision grinding is often applied as a final machining procedure for diverse components of varying sizes, ensuring accuracy and high productivity rates. They include automotive, aviation bearing, electrical, medical, etc. Here are some common applications of precision grinding:

• Micro-finishing of flat and cylindrical surfaces
• Grinding machining of outer circles, holes, and hole systems
• Grinding of bearing surfaces
• Precise machining of aerospace fasteners, tubes, rods, wires, tools with blades, etc.

The precision grinding machine uses a rotatory grinding wheel consisting of abrasive particles to remove material from workpieces. Also, the grinder machine comprises an electric motor that delivers motion power to the abrasive wheel through the belt and pulley system. Most grinder motors rotate at a set speed of anywhere from 150 to 15000 rpm, which varies based on the type of grinding project.

You must follow several safety measures to use a grinder machine safely. Before operating the grinder, you should always wear Personal Protective Equipment (PPE). They help shield against sparks and other flying particles when grinding. PPE includes an apron, safety glass, glove, dust mask, hearing protection, safety boots, etc.

There are some notes to use grinders safely:

• Ensure the grinding guard is well attached.
• Use the right wheel for each grinding operation.
• Ensure the proper assemblage and tightening of flanges and other parts.
• Secure the workpiece to prevent deflections when grinding.
• Check and adjust the grinding speed to the right intensity.
• Ensure the work area is clean.

A typical grinder machine is made up of several components. Take a look at the main parts below:

• Grinding Wheel
• Wheel Guard
• Abrasive Wheel Head
• Traversing Wheels
• Base
• Table
• Column
• Coolant Supply Nozzle

Precision grinding operations are common in several industries today. Some manufacturing factories offer precision grinding services on-site, while others outsource it to companies specializing in this machining service.

At WayKen, we have the necessary on-site precision machining technologies and equipment to handle your projects. We take pride in our professionals with many years of experience and skills ready to accommodate your design specifications. Moreover, we assure high-quality, precise, long-lasting, and affordable precision machined parts at any volume.

Feel free to contact us today for one-on-one support service, and you will get a response within 12 hours.

Precision grinding remains one of the most effective and efficient machining techniques for fabricating and finishing parts with closely detailed tolerance requirements. It provides benefits such as cost-effectiveness and accuracy, straightforward quality control, and increased productivity. As a result, precision grinding is applied in many industries today to produce high-quality surface finishes.

What is the accuracy of the grinding machine?

Generally, the accuracy of the grinding machine varies based on the manufacturing project. This is because some rough grinding operations rapidly remove high volumes of metal workpieces. However, in most applications, as a finishing process, the accuracy of the grinding machine stands in the order of +/- 0.000025mm. Experts often apply grinders to remove small quantities of metal anywhere from 0.25 to 0.50mm depth.

What is the cutting speed of the grinding machine?

The cutting speed of the grinding machine is ideal when set between 20 and 25 m/s. For most surface grinding operations, experts use wheel speeds of 30 to 35m/s. But keep in mind that grinder machines can be successfully applied with less than 1m/s speed. Besides, the cutting Cermet Inserts speed of a 0.2mm grinding pin rotating at 40,000 rounds per minute amounts to approximately 0.4 m/s.

Further, high-speed grinding operations involves using special wheels at cutting speed up to 100m/s. In most cases, high-speed grinding provides increased productivity and efficiency, as well as the improved tool life of the grinding wheel due to reduced grain loads.

If you are an industry worker, or if there is any case you ever work around tools, you would probably have to know what tool for what is and how are they made. Every cutting tool has its specialty and specification. Not to forget that every machinery and work need a different type of carbide insert whether in means of shape, design, coating, or manufacturing. However, if you are a newbie around the cutting tools, and want to get familiar with the jack of all tools-carbide inserts, I recommend you read this one till the end. It can be of great help.

First of all, let’s have a little introduction to carbide inserts.

A carbide insert is useful for accurately machining steels, carbon steels, steel alloys, cast iron, and a variety of non-ferrous metals. There are many styles, sizes, and quality levels of diamond inserts that can be replaced and indexed.

If we talk about the benefits being provided by carbide inserts they could be many. To sum them up, carbide inserts enable faster machining, which leads to better finishes because they can be used at high speeds. Furthermore, to avoid damaging the insert, the machine, and the workpiece, it’s vital to pick the correct carbide insert for the material that you’re cutting.

Got enough knowledge about carbide inserts? Great! Now it is time to move towards the center of attention of this blog. Yeah, you have heard it right. I am certainly talking about the insert grades. Every manufacturing industry has its carbide insert grade. Additionally, they provide a complete?carbide insert chart?for its users. But what is it?

Carbide grades are generally used as a term in metallurgy when referring to sintered WC materials that are used in nozzles, dies, rollers, crushing rolls, and cutting tools.

Depending on the machining application, an insert’s grade or material is designed to be suitable for that particular task. Even though two inserts may look similar, they may be different in terms of the material used for the basis and the coating.

Understanding carbide inserts are essential when choosing an insert. It is the most crucial thing, to begin with, the?carbide insert selection guide.?In insert selection, what matters is the shape of the carbide insert. In the guide below, we will be discussing the insert selection concerning its size and application.

Square-shaped inserts are the most commonly used carbide inserts. As we all are familiar with the square shape having a 90-degree angle, a square carbide also has sturdy 90-degree angled corners. It has an amazing economy with 8 edges on cermet inserts a double-sided insert. Furthermore, it is usually used in roughing face procedures. specifically, roughing through square-shaped inserts is done by castings, forgings, and rough sawed blanks. Despite many plus points, it lacks some points. It has been seen that sometimes, it is unable to turn. Furthermore, it needs high force to push it against the workpieces when used for turning. Moreover, it must always be used in a stable setup.

The next insert we have on our list is a diamond insert. It is a popular insert because of its versatility. It can be used on most materials with ease. It has a strong cutting edge and corners of 80 degrees each. As far as its application is concerned, it can be used for both roughing and facing. The opposite angles are 100 degrees which can be helpful for general roughing applications.

However, it can cause chip jamming because of less clearance between the trailing side and the workpiece of the insert.

Next, we have the trigon-shaped insert. It is not very common to use. Trigon is a six cornered, 80-degree diamond-shaped insert that can help increase the economy more as compared with other types of inserts. Its application can be on moderate depths. Meanwhile, it can not go into much depth.

You may have seen triangle carbide insert around you often. This is because it is a versatile shape that can have multiple uses including turning, facing, boring, copy turning, and basic profiling. Adding extra side clearance between the insert and the workpiece bore, these inserts are excellent choices for general boring. But, their edge is comparably weaker than those of 80-degree diamond insert. Furthermore, you must be opting for the right size of the carbide insert not a very large one.

A 55-degree diamond insert is preferred for profiling applications. It can plunge into a small diameter at a specific angle of 30 degrees. It can be used when machining near a tailstock. It may have the drawback of being weaker at the edges than a triangle insert.

A 35-degree diamond carbide insert could be a great choice for copy-turning. Similar to a 55-degree diamond insert it can also work close to the tailstock (closer than a 55-degree insert). However, it can be considered as one of the weakest shaped inserts having depths of cut lighter than others.

It is, therefore, best to use negative style inserts only externally in cavities. However, Positive Style can be used both externally and internally, and the increased cost per edge is often outweighed by the improved performance.

As in any application, grades are vital to the success of the application. As a result, the turning section of any supplier’s catalogue will offer the most grades.

Various turning applications have led to an extensive range of turning grades. These range from continuous cutting, in which no impact is suffered but lots of heat is generated, to interrupted cuts, which have heavy impacts.

From 3-millimetre, Swiss-style machines, to 100-inch, heavy-duty industrial machines, the range of turning grades relates to the wide range of diameters in manufacturing. Depending on the diameter as well as the cutting speed, different grades are suitable for either or both.

Usually, major suppliers provide their range of grades for the different materials. Grades range from tough to hard for interrupted cuts in each series.

For milling applications, there are fewer grades available compared to other applications. The fundamentally interrupted nature of milling tools calls for grades that are hard, impact-resistant, and able to withstand severe conditions. A thin coating is also important for the properties of the coating to withstand impacts, otherwise, it won’t be able to do its job.

It is common for suppliers to use a variety of coatings and tough substrates to mill a large array of metals and other materials.

It is important to note that due to the speed factors involved in cutting, the grade selection during cutting is limited. The diameter, as the cutting direction moves closer to the point, will become smaller. The cutting speed correspondingly decreases as the cutting direction moves closer to the point. Partitioning to the centre results in zero speed at the end of the cut, and instead of cutting, the operation involves shearing.

In other words, a grade for parting off should be able to handle a wide range of cutting speeds, and the substrate should be tough enough to withstand shearing after the operation.

A drilling tool has a cutting speed of zero at the center but varies at the periphery based on its diameter and spindle speed. It is not recommended to use grades designed for high cutting speeds. It is not recommended to use grades designed for high cutting speeds.

Consider the supplier’s catalogue or website for assistance in choosing the correct carbide grade for a given application. It is important to note that there is no formal international standard, but most suppliers use systems that describe grades’ recommended working envelopes by using their three-character “application range” i.e. P05-P20.

Following the ISO standard, the first letter on the list represents the material group. There are letters associated with every material group.

Based on a scale of 05 to 45 in increments of 5, these numbers show the relative hardness level of the grade. It is recommended that a hard grade suitable for favorable and stable conditions be used for a 05 application. Considering the conditions that exist in a 45 application, a very tough grade is required to handle potentially adverse ones.

As is the case with these types of values, there is no standard for them, so they should be interpreted as coming from the specific table of grades within the term they are used in. There could be a difference in hardness between grades marked as P10-P20 in two catalogs of two different suppliers.

Grade designations are also not governed by any official standard, just as grade ranges are not governed by an official standard. However, most major carbide insert suppliers follow common grade designation guidelines. Classic designations follow the format BBSSNN, where:

• BB?—Brand Code:?Each of the major suppliers has its letter.
• SS?—Grade Series Number:?A Grade Series Number is usually represented by two random digits that are assigned randomly. Generally, a series is made up of grades created for a single raw material and having the same type of coating.
• NN?—Hardness Level:?It normally indicates the hardness level of the grades within the series of digits that appear at the end of the standard number. In the same way, as the grade charts explained above, the number usually ranges from 05 to 45.

It should be noted that this is true for the most part. It is advisable to keep an eye out for these changes since this is not an ISO/ANSI standard.

Before choosing the correct insert angle, it is vital to consider many parameters first. To achieve good chip control and machining performance, carefully select insert geometry, insert grade, insert shape (nose angle), insert size, nose radius, and enter angle (lead angle).

• For example, if the operation is finished, you can select the insert geometry according to it.
• For strength and economy, select the insert with the largest possible nose angle.
• Based on the depth of cut you expect, select the insert size accordingly.
• You want the nose radius of the insert to be as large as possible to maximize strength.
• If vibrations are a frequent occurrence, it may be prudent to select a smaller nose radius.

Essentially, the grade of the insert is determined by several factors such as:

• Materials for component construction (ISO P, M, K, N, S, H)
• Method of processing (finishing, medium, roughing)
• Machine conditions (good, average, hard)Machine conditions (good, average, hard)

There are several advantages to having inserts with optimum geometries and grades. An insert geometry lacking strength can be compensated for by a grade with high toughness.

The type of steel grade to be used as part of an application should be carefully considered before selecting the material. In selecting the right tool, it is critical to consider the application as well as grade, cutting data, and tool wear. To make the right choice, it is also important to consider the existing grade, cutting data, and tool wear.

A hard and wear-resistant grade, such as CH0550, should be the right selection in a continuous H05 application, like turning the face of a gear and its internal diameter. Our testing wasn’t successful. Therefore, we can say that the main thing to consider when choosing a grade is to look at the application as well as to see what the competition is using. In terms of wear resistance versus toughness (ISO application area) chart, CBN060K has been available for a while, but it is still a very good grade in the HPT-chain, and fully capable of beating any competitor in the H15 area. A hard and wear-resistant grade such as CH0550 should be the right choice in continuous applications, such as turning the face and inner diameter of gear, a typical H05 application. But testing did not succeed. So making the right choice depends on your application and the material.

Posted on:? Aug 9, 2018, | By Vivi, WayKen Project Manager

Rudgley M defines rapid manufacturing as: “manufacturing technology for manufacturing the final practical product by additive manufacturing method”, which uses prototype manufacture technology to produce the desired product for production. Rapid manufacturing is a development direction of rapid prototyping technology, but there are still many areas for improvement.

SLA, SLS, FDM are the main technology for prototype manufacturer, and the common features of them are discreting the part into separate layers and make the layers independently.

The most tempting feature of rapid prototyping products is that they are almost unlimited in terms of geometry. With this process, articles with great independence and freedom of geometry can be produced, such as inverted concave, overhanging, free form, and various basic geometric shapes. For example, the SLS process requires no brackets, and the parts can be placed in any position in the machining position without the need for a clamp, which means that the SLS can provide nearly infinite geometric possibilities to the workpiece.

On the other hand, various products from micro to large sizes can be manufactured with rapid prototyping technology. The size of the product depends on the choice of process: SLS, SLA and FDM are usually used for the manufacture of medium-sized parts, because of the process execution and economic cost, as well as the performance of large-sized parts. The size of these processes is very limited when it comes to large products.

Since the polymer rapid prototyping technology does not require a mold similar to the conventional processing method, the customer-defined product manufactured by rapid prototyping is significantly more economical than the conventional process. This feature combined with the complex geometry that the product can achieve jointly point the way to rapid prototyping in the medical field. At the same time, the geometrical high flexibility also provides the possibility of combining RP with traditional processing methods, and has rapidly developed into one of the development directions of today’s RP technology. For example, the previous manufacture of thin-walled long and narrow parts can only be done with the EMD (Electro-Sparking) process, and now RP can also provide a complete solution for the manufacture of such parts.

With the rapid prototyping process, parts with features (such as concave, inner sharp corners, long thin walls, etc.) that cannot be machined or difficult to machine with conventional milling inserts machining methods can be easily manufactured. At the same time, in order to make RP technology work, designers must rethink the way they design parts to demonstrate the free design characteristics of these processes.

It is worth noted that all of the above questions about free design require further development of professional CAD software for RP technology. The combination of improvements in design tools and changes in designer design concepts can tap the potential of RP technology.

In addition to directly designing the model of the required product, engineers often design according to the existing physical design, which is called reverse engineering. Rapid detection and 3D CAD reconstruction techniques provide a way to obtain CAD models directly from physical objects.

The reason why RP technology is called Surface Milling Inserts “rapid prototyping technology” is that it produces products with a shorter cycle than traditional processing. The sensitivity of the RP to the design is very low. That is to say, the degree of flexibility of the production is high, and the shape problem of the product is hardly considered at the time of manufacture, thereby saving a lot of time. In view of this, many companies use RP technology to manufacture test pieces of products to quickly understand the performance and other parameters of the product.

Although the productivity of various RP processes has increased, the production requirements for RP productivity have not been met. In addition, due to the extreme unequalness that the RP process can provide, it also leads to considerable exaggeration of equipment and material losses.

At present, although RP technology has great advantages in product prototyping and product trial production, the high price and material loss of equipment and the difference in productivity with traditional processes limit the large-scale manufacturing of RP process. Of course, economy is just one reason why RP processes are rarely used to make long-lasting parts. Other major factors are product strength, material, process repeatability, and so on.

As far as the development of RP technology is concerned, there is still a gap between the manufactured products and the traditional manufacturing methods in terms of surface roughness, precision, repeatability and product quality. It can be said that the existing RP process and process chain must undergo a period of development to achieve a reliable and safe technology to achieve the precision and quality required by the process. The RP process mentioned above has almost the same precision (0.1-0.2mm/100mm) and roughness (Ra 5-20μm), and the repeatability is relatively low. Further improvements should be made from the mechanical design side, which can be achieved through a technical feedback system. It is foreseeable that to improve the quality of products, there will be a composite process equipment combining RP process and traditional process.

From the perspective of the equipment itself and materials, the main research directions are focused on processing methods, processing equipment, laser generators and materials, aiming to improve the strength, durability and precision of the products, and the cycle of the products. These studies will ultimately provide a powerful impetus for the rapid prototyping transition to rapid manufacturing.

In the field of components, 3D printing technology can be used to quickly produce complex products. In the field of traditional automobile manufacturing, the development of automotive parts often requires long-term research and development and verification. From the R&D to the testing phase, it is also necessary to make a part mold, which is not only long but also costly. When there is a problem, modifying the part structure and so on also requires the same long cycle. And 3D printing technology can quickly make complex parts. When there is a problem in the test, modify the 3D file and reprint it to test again. It can be said that 3D printing technology makes the development of future parts cheaper and more efficient.