It is quite difficult to choose the appropriate steel grade for handrails and railings. This is due to the fact that only a specialist can correctly assess the physical and chemical properties of the alloy in relation to the object on which these very handrails will be used.
For example, high-alloy stainless alloy AISI 201 is suitable for handrails used inside residential buildings and public spaces. However, this alloy is suitable only for heated buildings with normal humidity indicators.
Handrails for street ramps, for example, in suburban real estate, are made of AISI304 steel - an austenitic alloy with a reduced carbon content. However, such railings are suitable only for objects located far from fresh and salty reservoirs.
For handrails at swimming pools, saunas, baths, as well as for outdoor handrails that are located near reservoirs, the sea in the vast majority of cases use Ultra AISI 316L alloy.
Why not every alloy is suitable for handrails
Under the influence of the external environment, regardless of whether the handrail is located outside or inside the room, the metal is susceptible to destruction. This process is called corrosion. The chemical element chromium is responsible for the corrosion resistance of the alloy, the higher its content in the alloy— the higher the corrosion resistance.
To understand the process, it is worth considering that corrosion can also be different. Metal collapses from exposure to chemicals - for example, flue gases, also emit electrochemical corrosion - in contact with acids, alkalis, seawater.
So-called austenitic corrosion-resistant steels are used for handrails, which are resistant to electromechanical corrosion. In everyday life, such an alloy is called "stainless steel", "stainless steel", meaning that the chromium content in the alloy exceeds 17%.
In addition to the chemical composition of steel, the corrosion resistance is also influenced by the method of mechanical processing. In the process of grinding, for example, micro defects arise, which subsequently become foci of corrosion. For this reason, polished stainless steel for handrails resists corrosion much more effectively than, for example, polished. Let's take a closer look at the alloys for handrails and their characteristics.
AISI 201
This stainless alloy belongs to budget options and has proven itself well as a material for indoor railings, provided that normal air humidity indicators are observed. Corrosion resistance should be considered high if used under standard conditions — in a heated residential or non-residential premises where acid and alkali exposure is not expected.
AISI304
If stainless steel railings are to be installed outdoors, in rooms with high humidity, AISI 304 alloy is often chosen. It is suitable for use if constant contact with water is not expected — that is, it is possible to install AISI304 stainless steel handrails in the dry part of the pool or sauna, at a country house that is far from reservoirs.
AISI304 assumes an increased content of chromium and nickel in the composition, which makes corrosion resistance 5 times higher than that of AISI 201. Also, this alloy perfectly manifests itself in contact with steam — in saunas, baths, fonts, or rather — in their dry areas.
AISI 316
This alloy has proven itself well as a material for handrails, railings, fences in an environment with high aggressiveness. For example, such handrails can be installed in wet areas of swimming pools, baths, near the sea or other bodies of water. The physical and chemical properties of the alloy are improved by the inclusion of molybdenum (2.5%). This chemical element provides increased resistance to corrosion, chemical influences and other aggressive environments.