Stainless steel angles are the profiles that are used the most and for the most applications amongst the commodities. Depending on the production technology, there are different types.
Angle bars in stainless steel are available in the same dimensions like the ones in carbon steel (S235-S355). This fact allows an easier calculation and congruent planning. This is especially regarding projects, which need the advantages of the corrosion resistant characteristic of stainless steel angles. Due to their geometry, we also call angle bars L-profiles. In general, L-profiles are available in the following stainless steel grades: 304 and 304L, 316 and 316L as well as 316Ti. Angle bars are the most basic stainless steel profiles for structural application.
Equal stainless steel angles are the most common ones. The smallest available size is 10x10x2 millimetres. Looking at bigger sizes, stainless steel angles can reach up to 200x200x20 millimetres. Bigger angle bars are usually special profiles with very rare use.
Unequal stainless steel angles also follow the sizes of the carbon steel counterparts. The smallest is the size of 20x10x3 millimetres and the biggest 200x150x15 millimetres. The standard length of stainless steel angle bars is 6 metres.
Depending on production, technology and use, there are different types for angle bars in stainless steel and carbon steel.
Hot rolling of stainless steel angles is the most cost-efficient production method. It is not very costly and complex to hot roll L-profiles. Therefore, it is the economic alternative to achieve the commodities. However, with this technology one receives a product with limited re-quirement in regard of the tolerances, round angles and an internal radius, which can be up to the double amount of the material thickness.
Cold rolling of angle bars in stainless steel grants a fine and bright profile surface. These profiles have tight tolerances and, on the inside as well as on the outside, very small radii.
Such stainless steel angles will often be used in aesthetic applications, e.g. in the furniture construction. They are also often mirror polished, which appears to be easy, due to the already smooth surface.
The available dimensions of cold rolled stainless steel angles are limited though, and reach only the size up to 60x60x6 millimetres.
Cold drawing of angle bars in stainless steel is another production method, which allows very precise sections. The tolerances for these stainless steel profiles are within the h11 scope. All corners are sharp and there is no inner radius.
The dimensional range for cold drawn stainless steel angles is similar to the one of cold rolled L-profiles. Production lengths lie between 3 to 4 metres. They also are used in aesthetical applications. However, the biggest range of use is for machine construction, where the high level of precision and dimensional accuracy is needed.
The worldwide annual consumption for angle bars bigger than 150 millimitres is so low that it does not reach the minimum quantity for the hot rolling process. Therefore, laser welded stainless steel angles will be the better choice. We produce the L-profiles by welding together two stainless steel flat bars. The result is sharp edged, has a marginal inside welding seam at a maximum of two millimetres and has tight tolerances.
Cold forming and press braking are two other similar technologies to produce angle bars. Both production methods have in common, that they generate a bend radius on the inside and outside. The strong cold deformation leads to a cold work hardening of the stainless steel, which is not only undesirable but can also have other negative consequences.
When cold forming, flat bars are guided into a rolling stand at room temperature. There they will be rolled until they reach the desired shape. We use this method for geometries with little and thin-walled sizes. Quite often, a minimum quantity of a few kilometres are necessary to cold form.
Press braking on the other hand is to produce single bars only. A particular mould and arbor press forms a flat bar positioned in a trimming press to a stainless steel angle.
Depending on the press capacity of the machine, it can form material thicknesses up to 20 millimeters. Usually, the press braking technology creates very big stainless steel angles, where one angle leg can be up to one metre.
Every production method for stainless steel L-profiles has advantages and disadvantages.
|Technology||Productivity||Low-cost||Minimum quantity||Dimension range||Quality|
|Hot rolling||Very high||Yes||Yes||Wide||Low|
|Cold rolling||Medium||No||Yes||Limited||Very high|
|Cold drawing||High||No||No||Limited||Very high|
The last three described production methods are also suitable for manufacturing special profiles according to the customer’s preferences.
Here, laser welding outreaches all the other technologies in terms of flexibility and possibilities to customize the L-profile.
The raw material for this are high-quality hot rolled sheets. Welders can combine them freely with different thicknesses to create the special angles. This diverseness in the material thickness of web and flange is not possible for press braked or cold formed profiles.
Furthermore, the customer can decide on the bar length according to his individual needs.
Besides the above-mentioned stainless steel grades, stainless steel angles are very seldom available in other grades. Special grades for stainless steel profiles are almost always exotic and therefore we have to manufacture them on project basis.
Not suitable are all manufacturing methods that require minimum quantities. The best technologies are press braking and laser welding.
However, there are limitations: Not all stainless steel grades are applicable for laser welding. Grades with a high content of sulphur and phosphor can cause cracking in the weld seam for example.
On the other hand, we cannot press brake all stainless steel grades either. We can press brake firm steels, like Super Duplex stainless steel, without causing cracks in the material only conditionally.
In general, the most stainless steel grades are applicable to produce L-profiles: from ferritic stainless steel and austenitic stainless steel to Duplex stainless steel.