In every machining system, one simply can't ignore the important role that cutting tools play. Oftentimes, the quality of a finished product would rely on the quality of the cutting tools. The quality and the performance of cutting tools would also directly affect a machining system's overall productivity. It is because of their importance that manufacturers would take into consideration several criteria before eventually buying a piece of cutting tool for their machining system. Included in these criteria are the tools ability to last long under rigorous operating conditions and their capability to perform at very high speeds. Also important is the tool's resistance to wear and tear, including resistance to breakage, edge and flank wear, cratering or top wear, chipping, built-up edge (BUE), deformation, and thermal cracking.



1. Kinds Of Tools

As the demand for better cutting tools increase, cutting tool suppliers also continuously develop products that can pass manufacturers? demands. Through the years, a lot of materials for the manufacture of cutting tools have been experimented upon; some have passed the standards while others were simply dropped. Today, there are only two types of cutting tools heavily favored in the machining industry: high speed steel (HSS) cutting tools and carbide cutting tools; and it seems that carbide cutting tools have slightly overtaken the other in popularity. So, what advantages do carbide cutting tools have over their HSS counterparts? Considering their lead in popularity, it is clear that the benefits of carbide cutting tools outnumber that of HSS cutting tools. And we'll understand these benefits better if we know what carbide really is.

2. What is Carbide?

In chemistry, carbides refer to any group of compounds made up of carbon and one other element that can be a metal, boron, or silicon. There are actually many compounds belonging to this group, among the more popular of which includes:

- Calcium Carbide

- Aluminum Carbide

- Silicon Carbide

- Tungsten Carbide

- Iron Carbide

3. Industrial Uses of Carbide

In the 20th century, carbides have been used for a lot of industrial applications. Carbides used in industrial applications are often called cemented carbide products and are classified in three major grades:

- Wear grades

Used primarily in dies, machine and tool guides

- Impact grades

Higher shock resistance carbide products used for dies, particularly for stamping and forming

- Cutting tool grades

Carbide tools used for cutting

4. Carbide Cutting Tools

Cutting tool grades of carbides are further subdivided into two groups: cast-iron carbides and steel-grade carbides. As their name implies, cast-iron carbides are specifically made for cutting cast-iron materials. These carbides are more resistant to abrasive wear, protecting the carbide cutting tool from edge wear due to the high abrasiveness of cast-iron. Steel-grade carbides, on the other hand, are specially made to resist cratering and heat deformation that may be caused by the long chips of steel on higher cutting speeds. Whichever grade of carbide is used in a carbide cutting tool, the main carbide material used in its manufacture is tungsten carbide (WC) with a cobalt binder. Tungsten carbide is well known for its hardness and resistance to abrasive wear. Cobalt, on the other hand, is used to further toughen the tool's surface.

5. Other Variants

Aside from tungsten carbide and cobalt, other alloying materials are added in the manufacture of carbide cutting tools. Among them is titanium carbide and tantalum carbide. Titanium carbide helps the carbide cutting tool to resist cratering while tantalum carbide can reduce heat deformations in the tool. Also commonly used in the cutting industry today are coated carbide cutting tools. Aside from the basic carbide materials, titanium carbide, titanium nitride, ceramic coating, diamond coating or titanium carbonitride are used as coating materials. The different coating materials aid the carbide cutting tool differently, although they are generally used to further toughen the cutting tool.

6. Benefits of Carbide Cutting Tools

- Toughness

- Exceptional resistance to abrasion

- Superior wear resistance

- Resistance to cratering

- Resistance to thermal deformations

- High modulus of elasticity

- Chemical inertness

- Torsional strength twice that of HSS

- Compressive strength