Steel's popularity as a jewelry material, especially in men's jewelry, has increased in recent years. Steel is an iron-carbon alloy that has been used for millennia in crafting tools, structures, and manufacturing. Stainless steel was developed in the 19th century with a composition of 10 percent chromium and 0.15 percent carbon added to iron. Stainless steel resists corrosion better than earlier alloys. It does rust, but the rust (or oxide) is a thin layer that protects the metal from reacting with water or air. With its attractive grey color, strength, and relatively low cost, stainless steel jewelry is a good alternative to pricier metals such as silver or white gold. Stainless steel jewelry and watches resist tarnish and are hypo-allergenic.
A common metal, titanium became valuable to industry in the mid-20th century as an indispensable aerospace material. Titanium has the strength of steel at about half the weight and can be alloyed with other metals to enhance its properties. Titanium is also hypo-allergenic, unless alloyed with nickel, making it suitable for medical equipment and implants, including artificial hips. These properties make titanium an excellent choice for body jewelry.
Also called wolfram, tungsten was first distilled from the mineral wolframite. It forms extra-dense alloys when added to other metals, and these alloys are used in products ranging from golf club heads to weapons. Tungsten is as strong as steel and about twice the weight. Tungsten resists scratches, corrosion, tarnish, and discoloration much better than the other industrial metals. Tungsten Jewelry can be white (silvery grey) or black.
Tungsten carbides are compounds of tungsten and carbon: monotungsten carbide (WC) or ditungsten-carbide (W2C). A tungsten carbide compound is denser than silver, steel, or titanium, and tungsten carbide jewelry is effectively wear proof. Pure tungsten jewelry is available; however, pure tungsten is not as hard as the carbides. Tungsten carbide jewelry is dark grey or black.
Surgical stainless steel is a steel alloy composed of iron, carbon, 12-20 percent chromium, 8-12 percent nickel, and 0.2-3 percent molybdenum. This steel is scratch-resistant, and it resists corrosion, even after multiple cleanings. It is called surgical because many medical implants and surgical tools are made of it. Body jewelry, especially belly rings, crafted of surgical stainless steel offers consumers a hygienic product.