What is tungsten carbide?

Tungsten carbide is a compound of tungsten and carbon. It enjoys a high reputation in industry because of its excellent durability and high melting point (2870 ° C). It is widely used in applications requiring high wear resistance or strong impact resistance, such as metal abrasives, cutting tools, molds and mining punches.

Tungsten itself is a dense light gray metal with a melting point of 3422 ° C and very high corrosion resistance. Its hardness is similar to that of hardened steel or emerald (Mohs hardness is 7.5). It also has considerable ductility and can be extruded into wire; Therefore, most incandescent bulbs use tungsten as the filament. It is also used in professional welding applications and medical equipment.

Brand and application of tungsten carbide

When alloyed with carbon, the Mohs hardness of tungsten increases to 9.0, which is slightly lower than that of diamond. This scratch resistance can be used in the manufacture of wear-resistant parts, such as saw heads or drills, equipment used in the manufacture of bricks and roof tiles, or crushing machinery. Its durability also makes it popular in the oil and gas industry. They are ideal for components required in harsh seabed environments.

The chemical symbol of tungsten carbide is WC, although it may be abbreviated to carbide in industry (although the name also applies to other similar compounds, especially titanium carbide and tantalum carbide). In its natural state, it is a fine gray powder that can be sintered (compacted by heat or pressure) to the surface or cemented (combined with metal to form a solid).

The grade of tungsten carbide depends on the binder used - usually cobalt or nickel. Other carbides can be added to improve specific properties, especially in terms of density, hardness or transverse fracture strength.

Carbide Burrs

Cemented carbide rotary burr, commonly known as rotary file or die grinding head, is used for cutting, forming and grinding, as well as removing sharp edges, burrs and excess materials (deburring).

Useful tip: to drill holes in hard metal, you need to use cemented carbide micro drill or cemented carbide straight shank drill. For grooving, grooving, profiling, contour machining, counterbore and reaming, you will use cemented carbide end mills, cemented carbide slot drills or cemented carbide milling cutters (Kone Carbide: The Best Carbide Tool, Blanks Supplier). For cutting and shaping stone or glass, you can use diamond burr.

Carbide Drill Bits

Carbide (CARB) is the hardest and most brittle material in bit materials. It is mainly used for production drilling using high-quality tool handles and equipment. It should not be used for hand drills or even drilling machines. These bits are designed for the most demanding and hardest materials.

Carbide Rings

You may want to know "what is tungsten carbide ring?". Tungsten carbide rings are made of compound tungsten and carbon atoms. Before making the tungsten ring, it starts in powder form and is then pressed together to form the desired shape. Tungsten rings have become a popular ring choice because of their hardness. It is much harder than diamonds and pure gold rings. It is also 10 times less likely to scratch than any other ring.

Carbide VS. HSS (High Speed Steel)

Generally speaking, the main characteristics of all high-speed steels are high working hardness and excellent toughness. HSS tools also cost less than cemented carbide tools, and are usually a good solution for "multi variety, small batch" applications.

Cemented carbide is harder, so it has longer tool life and faster cutting data than traditional high-speed steel. However, the disadvantage of this hardness is brittleness, so the cutting edge of cemented carbide tools will break or break quickly in some cases. HSS can indeed surpass cemented carbide due to its toughness in the following applications:

  • Poor clamping of parts to be processed
  • The setting is not strict
  • The tool is of long-distance type and overhangs excessively from the tool holder
  • The spindle of the machine tool is in poor condition

Let's look at three common machining operations - drilling, tapping and milling - to better understand when to use high-speed steel or cemented carbide tools.

Drilling

Cemented carbide bits are usually used for mass hole production, in which the higher tool cost can be proved according to the cost of each part. For deep and large capacity holes, they are usually equipped with internal coolant pipes to prolong tool life and stabilize production. The use of through spindle and high-pressure coolant can provide excellent chip removal effect, especially in deep holes (> 3XD), and it is the most effective way to cool the cutting edge.

Importantly, the higher hardness of cemented carbide tools in small batch production is reasonable, because they can process harder materials, possibly up to 70 + HRC.

HSS bits have a wide range of applications - from handheld applications to small batch CNC processing - due to their toughness and low cost. They are ideal for less rigid applications, such as hand-held drilling, laminated drilling, and deep hole drilling that cannot use an internal coolant supply.

Tapping

HSS tools are usually the first choice for tapping. They are by far the most common internal thread production. Recently, there are many hss-pm versions available for various CNC machine tool tapping applications, different thread types and material groups.

HSS taps are even used in mass applications and difficult to process materials, especially hss-pm taps. They are still preferred because of the process stability they provide.

Due to the brittleness of cemented carbide, cemented carbide taps are not so popular. In most tapping applications, it tends to produce debris, especially in blind holes. Cemented carbide will break in full depth in steel applications when the tap reverses and breaks the chip generated from undercutting to exit the hole. As mentioned earlier, high speed steel has better toughness than cemented carbide, which is indeed the most important in the tapping process.

Milling

Carbide end mills are by far the most popular because they provide the best metal removal rate (MRR). Integral carbide end mills have become the first choice because variable screw design, combined with CAM software package, provides tool path to suppress chatter caused by natural vibration in milling. Milling strategies such as cycloid method are now very common.

HSS end milling cutter still has a place, such as for manual milling machine, small volume, less rigid setting, etc. However, due to the progress of many industries, their use has declined recently.

FAQs

How strong is tungsten carbide?

How strong is tungsten? Tungsten's strength lies in its scratch resistance, which can only be surpassed by diamonds. If enough force is applied, it will crack, but its hardness is four times that of titanium and twice that of steel.

Which is better tungsten carbide or titanium?

Tungsten is not always a better choice than titanium. Of these two metals, tungsten is the strongest and more scratch resistant. Tungsten carbide has a hardness rating of 8.5 to 9, while titanium has a hardness rating of 6. Tungsten can only be scratched by metals or materials of the same or higher grade (such as diamonds).

Is tungsten bulletproof?

"Tungsten can make very good bullets," military analyst Robert Kelly told me. "This kind of thing, if you fire at someone's armor, it will go straight through it and kill it." They can penetrate thick steel armor and cause terrible but very local damage.