What you need to know about 304 and 316 Stainless-Steel

What you need to know about Stainless-Steel Cookware

In 1915 the New York Times reported on the development of stainless steel in Sheffield, England. Elwood Haynes an American inventor, metallurgist, automotive pioneer, entrepreneur, and industrialist invented the metal alloy stellite (chromium with cobalt), and independently co-discovered stainless steel along with Englishman Harry Brearley.

Stainless steel is an iron alloy with added elements. SAE sets a minimum of 10.5 percent chromium to qualify as stainless steel. Depending on the grade, it may contain much higher chromium levels, and additional alloying ingredients like nickel, molybdenum, titanium, vanadium, nitrogen, phosphorous and selenium. The two most common stainless-steel grades are 304 and 316. The properties of the final alloy can be fine-tuned by altering the amounts of the various elements. For example

T304 and T304s surgical quality stainless steel contains 18 to 20% Chromium and 8 to 10.5% Nickel, and contains up to 25 additional elements including manganese, silicon, carbon, steel, and Titanium for heat and corrosion resistance. T304s includes Selenium to improve machinability providing a long-lasting shine and easy cleanability

316ti surgical quality stainless steel is a 16/10 (16 parts Chromium 10 parts nickel) solid solution of carbon in a nonmagnetic form of iron using the alloy addition molybdenum to promote resistance to acids. It is also known as marine grade stainless steel due to its increased resistance to chloride corrosion compared to type 304. 316ti includes titanium for heat and corrosion resistance.

439 ferritic stainless steel with increased chromium for improved high temperature corrosion/oxidation resistance, is a ferritic grade, used for the outer shell of cookware for induction compatibility.

Stainless Steel Terms

Stellite is a non-magnetic alloy which contains a variety of different metal components with the main elements being chromium with cobalt that melts and binds the hard metal carbides.

Chromium is a steely-grey chemical element that is a lustrous, hard, and brittle transition metal. Chromium is the main additive in high-quality stainless-steel cookware, to which it adds anti-corrosive properties, and it is able to be highly polished while resisting tarnishing.

Nickel is the second most prominent element in high-quality stainless-steel cookware. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile.

Titanium is a chemical element with the symbol Ti. It is a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in sea water, aqua regia, and chlorine.

Molybdenum is a silvery metal with a gray cast, has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of the world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys to resist corrosion from acids and chlorides especially in cookware and cutlery.

Vanadium is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer somewhat stabilizes the free metal against further oxidation. Vanadium is what makes our cookware easy to clean.

Selenium added to stainless steel about 0.1 percent or more improves machinability providing a long-lasting shine and easy cleanability.

Ferritic stainless steel is a type of steel with a chromium content of 10.5 to 27% and a carbon content less than 0.1%. These stainless steels are magnetic and compatible with induction cooktops.

What’s the Difference between 3-Ply, 5-Ply, 7-Ply, and 9-Ply COOKWARE?

Before we get into the confusion it’s important to know that the best heat conducting pan ever is Cast Aluminum. If you go to any restaurant in town, they are most likely cooking in an Aluminum or Aluminum Coated skillet. Why? Aluminum is cheap and it is the best cooking pan period.

However, aluminum is nothing more than electrified clay (DIRT). It’s a very soft metal, and like dirt it will end up in your food. Secondly, if it’s coated aluminum, once you eat through the toxic coating then you get to dine on the aluminum. So, what’s the answer?

• 3-Ply Stainless Steel Carbon Core Waterless Cookware is typically a cast iron pan CLAD with 18/8 stainless steel inside and out. This is relatively old technology found in the first waterless cookware brands sold through in home dinner parties in the late 1940’s to mid-1970’s. Sets sold for $300 to $700.
  • 18/8 Stainless Steel
  • Carbon Steel Core
  • 18/8 Stainless Steel
• 3-Ply Stainless Steel Aluminum Core Cookware introduced by All-Clad in the 1970’s is still made about the same today without any major improvements or developments. Average cost today for 3 pans is about $450. It’s 50-year-old technology and cannot cook waterless or greaseless.
  • 18/10 Stainless Steel
  • Aluminum Core
  • 18/10 Stainless Steel
• 5-Ply and 7-Ply with Encapsulated Bottom. By the late 1970’s the solutions to the sticking and burning problems of the 3-Ply pans was to add an aluminum encapsulated bottom to the 3-Ply pan.
  • 18/10 Stainless Steel
  • Carbon Steel Core
  • 18/10 Stainless Steel
  • Single Aluminum Disc Bottom for 5-Ply
  • Or a 3-Ply Disc made of pure, alloy and pure Aluminum for a total of 7-Plies
  • Encapsulated 18/10 Stainless Steel to cover the aluminum
• 5-Ply Full-Body Aluminum Core Waterless Greaseless Cookware introduced in the early 1980’s featured 304 stainless-steel with a unique combination of elements. It didn’t stick and burn like 3-Ply and had better release properties. It was the best cooking pan ever made and, in many respects, still is until this very day. In the mid 2000’s a 439 Ferritic Stainless Steel replaced 304 Stainless Steel
  • 1983 – 2005 5-Ply
    • T304 Surgical Stainless Steel
    • 1145 Pure Aluminum
    • 3003 Aluminum Alloy
    • 1145 Pure Aluminum
    • T304 Surgical Stainless Steel
  • 2006 – 2016 5-Ply Magnetic Induction
    • T304s Surgical Stainless Steel
    • 1145 Pure Aluminum
    • 3003 Aluminum Alloy
    • 1145 Pure Aluminum
    • 439 Magnetic Stainless Steel
  • 9-Ply Ultra-Tech II Magnetic 316ti Waterless Greaseless Cookware. In January 2017 Ultra-Tech was introduced. The most revolutionary waterless greaseless cookware ever developed with numerous patented features; Whistle Vent that tells you when to turn the heat down. A thermometer in the lid tells you about the temperature in the pan. See Ultra-Tech II HERE
    • 2017 – Present 9-Ply 316ti Magnetic Induction.
      • 316ti Surgical Stainless Steel with Titanium (cooking surface)
      • 1145 Pure Aluminum
      • 3003 Aluminum Alloy
      • 1145 Pure Aluminum
      • 439 Magnetic Stainless Steel
      • 3-Ply heat diffuser disc made of pure, alloy and pure Aluminum
      • 439 Magnetic Stainless Steel encapsulated bottom covers the aluminum plate.