On the Origin of Stainless
Despite being one of the most popular types of metal in the world, stainless steel is a fairly recent invention. Though the idea of a stainless steel was proposed in 1821 by a French metallurgist, it wasn’t until 1872 that two Englishmen invented an alloy that could be considered modern stainless steel. However, the uses of such a material were instantly appreciated. Consequently it became very popular quickly.
In fact the German steel firm Krupp achieved much of its success by developing new types of stainless steel and pioneering how to manufacture things with them. Notably, Krupp eventually became part of thyssenkrupp, the parent company of Online Metals. Krupp built everything from train parts to cannons out of stainless. Then, in 1908 Krupp went one step further and built a stainless steel hulled ship, Germania. This had never been done before.
Stainless steel, also known as “inox” from the French word inoxydable, is a steel alloy with a minimum of 10.5% chromium. This chromium is what makes it “stainless.” It is worth noting that the name is a bit misleading, as all of this material will rust eventually, it just takes much longer than mild steel. This resistance makes it popular in a huge range of uses though. Cookware, cutlery, household hardware, surgical tools, appliances, industrial equipment, automotive parts, aerospace parts, storage tanks, and building parts all commonly use stainless steels.
What’s the T-bar good for?
This particular product is made of the 304L (meaning Low-carbon) alloy. The stainless steel T-bar is typically used in structural applications where corrosion resistance is a priority. The higher levels of chromium in the 304 alloy gives it excellent corrosion resistance except if it is exposed to chloride solutions or marine environments it will begin to rust fairly quickly.
The shape of the stainless steel T-bar also makes it great for projects that require load bearing. The top portion of the T (flange) resists compressive stresses, where the bottom (web) resists shear stresses and prevents the flange from bending or buckling.
Lastly, stainless steel T-bar is weldable and provides good heat resistance, but it cannot be hardened by heat treating. Also, as it is a stainless steel it is somewhat more difficult to machine unless you have the proper tools and techniques.
304L Stainless Steel T-Bar Mechanical Information
Rockwell hardness – B70
Ultimate Tensile Strength – 73,200 psi
Yield Tensile Strength – 31,200 psi @ strain of .20%
Elongation at break – 70%
Modulus of Elasticity – 28,000 ksi
Shear Modulus – 11,200 ksi
Melting Point – 2,550-2,651 °F
304 Stainless Steel T-Bar Chemical Information
Carbon (C) – 0.08%
Chromium (Cr) – 18-20%
Iron (Fe) – 66.345-74% as remainder
Manganese (Mn) – 2%
Nickel (Ni) – 8-10.5%
Phosphorous (P) – 0.045%
Silicon (Si) – 1%
Sulfur (S) – 0.03%