The precise formation of tungsten and tungsten alloy rods is accomplished by one of two processes: swaging and continuous rolling. With decades of knowledge and expertise in the use of both methods, CHEMETAL USA offers clients the highest-quality rods to meet exacting specifications for almost any application.
Tungsten rod formation requires great skill and technological capability. In swaging, the rod shape is created either by forcing the metal through a confining die to reduce its diameter (known as “tube swaging”); or by using two or more dies to hammer and press the metal as it rotates (known as “radial forging.”) In the latter process, sintered tungsten billets are heated to 1,400-1,600°C in a hydrogen atmosphere, then deformed into solid rod shapes on various machines.
Continuous rolling in Y-type mills is a more advanced process yielding higher production efficiency. Tungsten rods shaped this way have a more homogenous microstructure.
Tungsten Rod Cutting and Sawing
Tungsten Carbide Cutting Tools
You’ve heard the old saw (no pun intended) that “only a diamond is hard enough to cut another diamond?” Actually, the specialized blades used to cut diamonds are made with diamond-tipped phosphor bronze or diamond-dusted steel.
In a similar way, blades that can cut through the toughest metals are made from a binary compound of carbon and another element, e.g., “tungsten carbide.” Technically, these are “cemented carbide composites,” held together on the blade’s base (often steel) with binders such as nickel, iron, or cobalt. The composite layer is adhered to through various methods, including brazing, welding, pressure bonding, etc.
Why not use diamonds to cut tungsten? The problem is that diamonds are unstable at very high temperatures. Their chemical properties change above 800℃ in air, losing strength and reacting with iron, making them unsuitable for machining certain metals.
While there are many types of carbide cutting tools, tungsten carbide is the first choice for most applications due to its extreme hardness, wear, and impact resistance.
The typical grades of cemented carbide composite blades used by CHEMETAL USA to cut tungsten rods are YG6, YG8, YS2 (YG10H), and 726.
CBN Cutting Tools
CBN (Cubic Boron Nitride) material is another good choice when it comes to the materials suitable for tungsten machining work. The main CBN cutting tools are CBN turning inserts and grinding wheels. Compared to Tungsten carbide, CBN has a cutting speed three times faster and is twice as wearable.
Cutting Edge Angle
A 45° rake angle (KAPR) is the recommended cutting angle between the tungsten rod and the edge of the insert. This is because the tungsten rod and billet are usually formed by sintering and often brittle due to its large grain size. A correctly applied cutting angle in the cutting and turning can efficiently avoid the edge and surface from being cracked or layered.
In order to prevent the tool used to cut tungsten rod from wearing down, the feed rate needs to be gradually reduced while the insert is entering or exiting the tungsten working piece.
CHEMETAL USA is a leading tungsten supplier and manufacturer in worldwide. Please check our tungsten rod to learn more information about tungsten rod products.