For security screens in Perth to provide adequate protection, strength alone won’t be enough. They will also need to resist constant exposure to a salty, humid environment like the coastal areas of the city. As elementary science goes, steel and water— not to mention seawater— don’t exactly go hand in hand.
Stainless steel was made for this kind of environment. Unlike regular steel, stainless steel is an alloy of iron and other metals that give it its corrosion-resistant properties. Among the most commonly used grades are 304 and 316. They differ in metal content, but they’re both modifications of the original recipe for regular stainless steel.
Chromium is the most popular metal in stainless steel, giving it resistance to oxidation. Today’s standards require stainless steel to contain a minimum of 10.5 percent. Constant exposure to corrosive elements warrants an increase in the chromium content, in addition to other metals. The 316 grade is 16 percent chromium, 10 percent nickel, and 2 percent molybdenum.
Chemical analysis shows that the 304 grade doesn’t contain any molybdenum, which makes all the difference. Molybdenum is stainless steel’s best friend against chlorides and sulphur-based chemicals. As salt is part chloride (sodium chloride), security screen doors in Perth such as the ones from KNA Security can last against the corrosive conditions of the beachfront.
Other metals present in both grades, although in trace amounts, include phosphorous, silicon, sulphur, and manganese. Most of these metals reinforce the already-resilient stainless steel, resulting in a high-tensile screen door. A 4-kg block of hardwood hurled at 20 metres/second is no match for a screen door with a tensile strength of 900 MPa.
You can trust screen doors with 316-grade stainless steel meshes to stay strong and corrosion-resistant. This grade is also used in decking on boats and ships, as well as their equipment like anchors, handrails, and shackles. They’re also used in underwater applications such as oil rigs, although that grade contains more molybdenum.
Overall, 316 grade stainless steel is one of the toughest materials around. When fashioned with state-of-the-art security door technology, they form a formidable deterrent combination.
(Source: “Stainless Steel 304 vs 316 Stainless Steel,” Stainless Steel Blog, May 8, 2014)