Stainless Steel

Stainless steel is a clean, maintenance free, contemporary material used in many industries as well as its well known use in household goods.

All stainless steels have a high resistance to corrosion compared to mild steel, different grades having different resistance depending on the number and quantity of other elements incorporated into the alloy. Unlike mild steels, there is no need to apply protective coatings or galvanising to stainless steel.

Stainless steel is the generic name for a number of different alloys of iron used primarily for their resistance to corrosion. The key element is that they all have a minimum percentage of 10.5% chromium, although more is used in the grades fabricated by Pland. Other metallic elements, particularly nickel and molybdenum, may be added but the incorporation of chromium is the determining factor.

Chromium has a great affinity for oxygen and during manufacture of the steel a little of the chromium in the alloy forms a passive chromium-rich oxide layer that forms naturally on the surface of the steel. Although extremely thin, only 1 to 5 nanometres, this protective layer is invisible, inert, tightly adhering and self renewing. Because it is inert it will not react or influence other materials; its tight adherence means that it clings to the steel and its self renewing property means that if damaged the protective film reforms immediately.

The most common use of stainless steel is in cutlery, with grades 409 and 430 being used for everyday ware and the finest Sheffield cutlery using specially produced 410 and 420 for the knives and 304 for the spoons and forks. Grade 304 is more ductile and therefore suitable for objects that need to be shaped such as sinks and washbasins. Grade 316 is a more corrosion resistant alloy than 304.

The benefits of this versatile material range from the cutting edges of knives to the formability and hygiene factors in sinks, from the strength and wear resistance in washing machine drums to the aesthetic appearance of hollow ware and pots and pans.

This leads to the important point that the initial investment cost of producing a component or fabrication in stainless steel will generally be more expensive than using ordinary steel. This is not just because of the higher alloy cost, but also because it requires more work to shape and form. However the considerably better life cycle costs of stainless steel make it attractive because of much longer service life, lower maintenance cost and high scrap value on decommissioning and recycling.