What S235JR Hot-Rolled Steel Angle Bar Is
S235JR angle bar is a hot-rolled long product with two perpendicular legs forming an L-shaped section. It belongs to the family of non-alloy structural steels and is rolled from low-carbon square billet in the as-rolled condition. The section is simple and economical to produce, which is why it is one of the most widely traded structural shapes in the world.
Angles are used both as independent members, such as bracing, purlins, lintel supports and frame elements, and in pairs or groups as built-up components. The material is expected to combine reliable mechanical strength with good weldability and enough ductility to be cut, punched, bent and drilled without cracking. Delivery condition is normally hot-rolled; normalized or other heat-treated conditions are supplied only on request.
Grade Designation, Sections and Delivery Forms
The grade is defined in EN 10025-2, the European standard for technical delivery conditions of non-alloy structural steels. The designation is read as follows.
S - structural steel for general construction use.
235 - minimum upper yield strength ReH of 235 MPa for the thinnest thickness range.
J - impact testing is specified for the grade.
R - minimum Charpy V-notch impact energy of 27 J at the stated test temperature.
JR - test temperature of +20 °C, so the grade is not intended for low-temperature service. S235J0 and S235J2 extend the range to 0 °C and -20 °C respectively.
Section dimensions follow EN 10056-1, which covers equal and unequal angles, and tolerances follow EN 10056-2. Equal angles are produced from roughly 20 x 20 x 3 mm up to 200 x 200 x 24 mm; unequal angles are grouped into equal-thickness and unequal-thickness series so that designers can tune the section to a specific load case. Standard mill lengths are 6 m, 9 m and 12 m, with cut-to-length bars available on request. Bars are supplied as-rolled, and can also be supplied blast cleaned, shop primed or hot-dip galvanized.
Chemical Composition
| Element | S235JR limit, ladle analysis |
|---|---|
| Carbon (C) | 0.20 % max for thickness up to 40 mm |
| Silicon (Si) | Not specified for this grade |
| Manganese (Mn) | 1.40 % max |
| Phosphorus (P) | 0.045 % max |
| Sulphur (S) | 0.045 % max |
| Nitrogen (N) | 0.009 % max |
| Copper (Cu) | 0.55 % max |
The deliberate limits on carbon, phosphorus and sulphur are what give the grade its fabrication behaviour: low carbon for weldability and formability, and low phosphorus and sulphur to limit segregation and cracking. Because carbon and manganese are both capped at modest levels, the carbon equivalent stays low enough that thin and medium sections are normally welded without preheating.
Mechanical Properties
| Property | Requirement |
|---|---|
| Minimum yield strength ReH, thickness 16 mm and under | 235 MPa |
| Minimum yield strength ReH, over 16 mm to 40 mm | 225 MPa |
| Minimum yield strength ReH, over 40 mm to 63 mm | 215 MPa |
| Minimum yield strength ReH, over 63 mm to 80 mm | 195 MPa |
| Minimum yield strength ReH, over 80 mm to 100 mm | 185 MPa |
| Tensile strength Rm | 360 to 510 MPa |
| Minimum elongation A, thickness up to 40 mm | 26 % |
| Charpy V-notch impact energy at +20 °C | 27 J minimum |
Yield strength falls as thickness increases because heavier sections cool more slowly after rolling and develop a coarser grain structure. When an angle is used in a deflection-controlled application, the stiffness of the section rather than the yield strength usually governs the design, and the same 235 MPa grade can be used across a wide span range.
Fabrication and Typical Applications
S235JR angles can be sheared, sawn, punched, drilled and welded with conventional shop equipment. Welding can use manual metal arc, MIG/MAG, TIG or submerged arc processes; consumables matched to a 360 to 510 MPa tensile range are the normal choice. Because the grade is impact tested only at +20 °C, it is not selected for structures that must remain tough at sub-zero service temperatures.
Building frames, roof bracing, purlins and lintel supports.
Plant structures and equipment support frames.
Crane and conveyor components, machinery bases and guards.
Ship and vehicle hull framing, supports and access structures.
Storage racks, shelving systems and warehouse equipment.
Cable trench supports, pipe racks and utility supports.
General fabrication where a weldable, ductile and economical section is required.
Frequently Asked Questions
Q: What does the JR suffix mean in S235JR?
The J indicates that impact testing is specified and the R fixes the minimum Charpy V-notch energy at 27 J. The test is carried out at +20 °C, which is why the grade is intended for ambient service conditions.
Q: What is the minimum yield strength of S235JR?
235 MPa for material up to 16 mm thick. The value steps down for thicker material, reaching 185 MPa for sections between 80 mm and 100 mm thick, because heavier sections cool more slowly and have a coarser structure.
Q: Is S235JR the same as ASTM A36?
They are close in strength and both are carbon structural steels, but they are not identical. A36 specifies a minimum yield strength of 250 MPa and a different chemical envelope, so substitution must be approved by the designer against the project specification.
Q: Can S235JR angles be galvanized?
Yes. The grade is routinely hot-dip galvanized for outdoor and marine-adjacent service. The surface is pickled and fluxed before the zinc bath, and the low silicon content keeps the coating appearance uniform.
Q: Is preheating required before welding S235JR?
For thin and medium sections it is normally not required, because the low carbon and manganese content keeps the carbon equivalent low. Thick sections, high restraint joints and cold workshop conditions may still call for preheat according to the welding procedure.
Q: Which sizes of S235JR angle are available?
Equal angles are commonly rolled from 20 x 20 x 3 mm to 200 x 200 x 24 mm, with unequal angles in both equal-thickness and unequal-thickness series. Standard lengths are 6 m, 9 m and 12 m, with cut lengths to order.
Q: What documentation is supplied with a batch?
An inspection document in accordance with EN 10204 type 3.1 is the normal requirement, giving heat number, chemical analysis and mechanical test results. Independent third-party inspection can be arranged when the specification calls for it.