The market size of Metal cutting machine (MCM) was estimated at USD5.99 billion in 2016. There is an increasing demand from several industries like the automotive, defense and aerospace, electrical and electronics, construction among others.
Abrasives are still a much-misunderstood method of cutting. Many people conclude that it results in rough surfaces due to its name.
So if you are wondering about what abrasive means, you are not alone. Abrasives define irregular shaped particles used to cut by chipping away material off the surface of a workpiece.
In choosing the right large diameter abrasive wheels, you need to understand the fundamentals first.
Read on to learn about the advantages and composition of large diameter abrasive wheels.
1. Result in Smooth Even Surfaces
Abrasive cutting wheels ensure you achieve precise metal cutting. They are applications that can handle tight tolerance and high precision.
Consider large diameter abrasive wheels if you are looking for a method that can achieve high-volume cutting at a moderate price.
The way large diameter abrasive wheels remove metal from the surface of the workpiece is its main advantage.
Their ability to grind and erode the workpiece helps you achieve a smooth and accurate surface.
2. The Grains Self Dress
These non-reinforced abrasive cutting wheels have countless sub-micron cutting particles. They self-dress when they get worn off.
The dull-edged grains usually break off to result in sharper cutting edges.
They have a continuous presentation of fresh cutting edges with each successive use. It ensures you don’t worry about maintenance.
3. Has a Wide Variety of Applications
Aside from rods and extractions, abrasive wheels can also be used for cutting tubes and dielectric materials.
You can easily cut composite and coated metals with no limits.
4. Abrasive Wheels Work at a Fast Rate
A grinder wheel works at a faster rate. When compared to other precision cutting methods-laser and electric discharge machine (EDM).
You can even bundle together the materials you need to cut for cost saving on high-volume cutting. This is an extremely effective advantage as you’ll also achieve a smaller diameter for a bundle with more materials.
5. Cut Extremely Hard Materials
Bench grinder wheels can achieve clean-cut surface finishes even with extremely hard materials. They produce the best surface finishes compared to other cutting choices.
Additionally, the cooled thin-wheel abrasives ensure little to no heat is produced. It’s very useful when working on workpieces.
6. There is a Variety to Choose From
There is an increasing development of synthetic abrasives. This adds up to the existing natural cutting abrasives.
If you are wondering about the meaning of abrasive? They are sharp, hard material used to wear away workpieces.
Even though their action is irregular, they result in a smooth, accurate surface. Besides, dull abrasive grains usually break away from the bonding material to result in sharper cutting edges.
Manufactured abrasives include;
Aluminum Oxide
Aluminum is usually used to manufacture abrasives of different degrees of purity. This helps achieve different griding levels. White aluminum oxide wheels for instance, grind high-strength heat-sensitive steel.
Silicon Carbide
Compared to Aluminum oxide, Silicon Carbide is harder and more brittle. Black silicon carbide can be used to cut cast iron, non-ferrous metals, and non-metallics. Green silicon carbide, on the other hand, is used to cut or grind cemented carbide as it is friable.
Cubic Boron Nitride
This is an extensively hard abrasive that enables you to achieve sharp and cool cutting.
It is among the newest manufactured abrasives. They are used on stainless steel, hardest cast irons, and super-hard high-speed steels.
You can use metal-coated CBN which has excellent boding adhesion for general-purpose grinding. Alternatively, there is uncoated abrasives which are suited for vitrified bond systems and electroplated metals.
Diamond
Even though natural diamond has been around for decades, synthetic diamond has gained popularity. This is due to its affordability.
Synthetic diamond is used to grind tough and very hard steels. Natural diamond, on the other hand, can be used to cut stone, cemented carbide and granite.
Types of Bonds
Bonding materials usually holds abrasive onto the cutting wheel. Below are standard bonds used on abrasive cutting wheels.
i. Vitrified Bonds
This is the most common abrasive used with large diameter abrasive wheels.
Vitrified bonds are usually made from ground clay and fluxes mixed. The preferred abrasives are usually added to this mixture and bonded to the cutting wheel.
ii. Resinoid Bonds
This is the second most popular bond which is usually phenolic resin that can be in powder or liquid form.
Resinoid bonds are used for rough grinding and cutoff operation.
iii. Silicate Bonds
Silicate bonds are usually ideal for keeping the heat generated during grinding and cutting at a minimum. Silicate bonds however readily release abrasives as compared to other bonds.
iv. Shellac Bonds
Shellac is an organic bond that enables you to achieve a smooth surface finish. It is however not suitable for heavy-duty operations.
v. Rubber Bonds
These are extremely tough and strong bonds that are specialized for centerless grinding machines. They enable you to achieve extremely thin finishes on workpieces.
vi. Metal Bonds
Last but not least, we have metal bonds that are used with diamond abrasives. They can be used for electrolytic grinding because metal is electrically conductive.
Abrasive Size (Grain and Grit)
The abrasive size is important because it usually influences the stock removal rate. Moreover, it influences surface finish obtained, as well as, chip clearance.
Abrasive size can be determined by the size of grains with and the characteristic of the grit.
Every grinding wheel has a number designating the grit characteristic. It is based on the size of individual abrasive grains in the wheel. Low grain size number translates to large grit and vice versa.
Below are levels of abrasives and the ration of grains to grit;
- Coarse 6-24
- Medium 30-60
- Fine 70-180
- Very fine 220-1,000
Wheel Shape Structure and Grade
When it comes to wheel shapes, you can have a cylinder, cup or dish wheels. There are also intermittent and continuous wheels.
Mounted wheels are those that are permanently mounted on a mandrel.
The structure of abrasive wheels is usually determined with relation to the pacing of abrasive grains on the surface of the wheel.
Finally, grade indicates the strength of the bonding material used.
Bottom Line
Large diameter abrasive wheels ensure you achieve smooth and accurate surface finishes. Working with the right abrasive supplies ensures you get what is suited for your shop.
We specialize in centerless wheels that can perform multiple tasks. Feel free to contact us to find out more about our products.