IS ALL STAINLESS STEEL THE SAME?
The 300 Series, Austenitic, stainless steel is most frequently used in architectural applications. Type 304L and Type 316L are the alloys most often specified for stainless steel doors and frames.
- 304 is basic chromium-nickel stainless steel that offers excellent resistance to corrosion and weather. It is the most commonly used alloy.
- 316 is a premium stainless steel containing an added element, molybdenum. 316 alloy offers corrosion resistance in heavy chemical or wet industrial atmospheres, and marine or coastal environments.
- The L designation indicates a low carbon variation of the alloy, which is favored when welding is involved in fabrication process.
Doors and frames are made from flat sheets of stainless steel cut from large coils; then cut, punched, formed, welded and finished. See the Finish section for more information on finish options.
CAUTION Galvanic Corrosion. This is a risk when dissimilar metals are in direct contact. To understand the reaction you need to know stainless steel's position on a galvanic series chart, and the relative mass of each metal in direct contact. On the galvanic series chart, stainless steel is a more noble metal than aluminum, mild steel, copper or brass.
Example: If mild steel was used for hardware reinforcements inside stainless steel doors and frames, galvanic corrosion would occur at the contact points and corrode the doors and frames from the inside out.
For more information on alloys, refer to Specialty Steel Industry of North America publication STAINLESS STEEL ARCHITECTURAL FACTS. Also refer to 
NAAMM-HMMA publication 866-01.
