Franke Stainless Steel

Seventy percent of sinks are made of stainless steel. As the world’s largest purchaser of stainless steel, Franke has its choice of the best raw materials. But that is only the beginning of the evolution from fine to Franke. By lavishing this material with cost, care and craftsmanship Franke creates a stainless steel that is “uncommon.” Let us tell you about the choices, the processes and the skills that Franke invests to raise its stainless steel systems to the quality, beauty and longevity its discerning customers deserve.

The reasons almost 70% of all sinks are stainless steel:

• Does not alter the essence and flavor of food
• Surface is easy to clean
• Requires very little upkeep
• 100% recyclable, making it right for today’s environmentally conscious world
• Resists corrosion and has hygienic and aseptic properties
• Does not require the labor-intensive application of an added surface treatment

Stainless Steel is an alloy of iron, chromium and nickel, generated to create advantages that individual pure metals do not offer. So it’s a whole greater than the sum of its parts. The name refers to the rust resistant properties of the metal: which is “stain-less”, but not “stain-proof.” These are its ingredients:

• Austenite is a nonmagnetic solid solution of carbon in iron, used in making corrosion-resistant steel of the kind used for making cutlery, hospital and food-service equipment, and tableware.
• Chromium (Cr) is a hard, malleable, glossy, gray, chemical element with no odor or taste, used in alloys to give them corrosion resistance and a glistening look. It is most responsible for the corrosion resistance of stainless steel.
• Nickel (Ni) is a hard, ductile, silvery-white, chemical element, a high-luster metal with a high level of corrosion resistance.
• Passivation Layer -- When stainless steel contains a sufficient amount of chromium, a hard, invisible, virtually impenetrable film of chromium oxide forms on the surface. Although only a few atoms thick, this prevents further surface corrosion when the stainless steel is exposed to corrosive materials and prevents any corrosion from spreading into the metal's internal structure. By definition, stainless steel resists corrosion, the gradual degradation of a metal or alloy especially by oxidation or chemical reaction. (Gold, platinum and palladium are the only metals not subject to corrosion.) But the level of corrosion resistance varies, based on factors in manufacturing:

                - Chemical composition of the metal

                - Temperature and temperature variations

                - Oxygen content and exposure to oxygen

Even slight variations in chemical compositions result in wide variation in quality. In other words, NOT ALL STAINLESS STEEL IS CREATED EQUAL.

There are several different types, and many different grades of stainless steel, so to deserve its “luxury” designation, Franke insists on creating and maintaining “differences that make a difference to you.”

“Gauge” describes the thickness of the sheet of stainless steel on a scale from 8 to 30, the lower the number, the thicker the sheet of stainless steel. Gauge is a significant factor because a heavier gauge can help prevent denting and bowing. It also contributes to noise reduction from garbage disposals and items making contact with the sink. That doesn’t mean though that thicker is always better. For instance, the thicker the gauge the more difficult, at times impossible, it is to “deep draw”, or craft from a single sheet to reduce welding marks, during manufacturing. So, Franke carefully selects the proper gauge, best fitted to the manufacturing processes.

• Franke full size deep drawn sinks are 16 or 18 gauge
• Franke full size hand fabricated sinks are 16 gauge
• Franke’s smaller accessory bowls are 18 or 20 gauge

The three most common grades available in stainless steel sheet metal are: 304, 316 and 410. Grade 304 is made up of at least 8% nickel (Franke’s contains 10%.) It is the most frequently used of the three grades, valued for its ability to provide corrosion resistance and to maintain the capacity of the sheet metal to be bent, welded, stamped and/or drawn. Franke relies on these properties to achieve the elegance and detail of its designs.

Franke insists on an alloy of 18% chromium and 10% nickel content by mass. This higher nickel and chromium content provides a level of corrosion resistance and integrity that is superior to any other category of stainless.

Franke Stainless Steel is ductile, meaning that it is malleable (moldable.) This ensures that it can be formed without cracking or breaking into parts.

Franke insists that its stainless steel be nickel-rich because when nickel is added the Austenite structure of iron is preserved. This crystal formation makes such steels non magnetic and less delicate at low temperatures. And it further contributes to the corrosion resistance. Franke places high value on two important physical properties:

• Thermal Conductivity - Austenitic stainless steels (i.e. T304 grade) have lower thermal reaction than carbon steels, helping you maintain the chosen water temperature in the sink.
• Thermal Expansion Rate - While stainless steel is most commonly used for its corrosion resistance it is also valued for its ability to endure exposure to high temperatures. Because of its high chromium content, Franke’s stainless steel has the added benefit of high temperature strength and resistance to scaling (oxidation) at elevated temperatures. Its chromium content accounts for its resistance to oxidation. As an austenitic steel, with chromium contents of at least 18%, it can be used at temperatures up to 1598 degrees, essential when working with pots and pans that need to be set down and are at temperatures upwards of 500 degrees.