Domestic Tungsten carbide

Tungsten carbide is used as the rotating ball in the tips of ballpoint pens to disperse ink during writing

Tungsten carbide can now be found in the inventory of some jewelers, most notably as the primary material in men's wedding bands. When used in this application the bands appear with a lustrous dark hue often buffed to a mirror finish. The finish is highly resistant to scratches and scuffs, holding its mirror-like shine for years.

A common misconception held concerning tungsten carbide rings is they cannot be removed in the course of emergency medical treatment, requiring the finger to be removed instead. Emergency rooms are usually equipped with jewelers' saws that can easily cut through gold and silver rings without injuring the patient when the ring cannot be slipped off easily. However, these saws are incapable of cutting through tungsten carbide. Although standard ring cutting tools cannot be used due to the hardness of this material, there are specialty cutters available that are just as effective on tungsten carbide as they are on gold and platinum. Tungsten carbide rings may be removed in an emergency situation by cracking them into pieces with standard vice grip–style locking pliers.

Many manufacturers of this emerging jewelry material state that the use of a cobalt binder may cause unwanted reactions between the cobalt and the natural oils on human skin. Skin oils cause the cobalt to leach from the material. This is said to cause possible irritation of the skin and permanent staining of the jewelry itself. Many manufacturers now advertise that their jewelry is "cobalt free". This is achieved by replacing the cobalt with nickel as a binder