20×20–200×200 · t 3–16 · St3sp / 09G2S · GOST 8509
Equal angle
Hot-rolled equal angle, legs 20–200 mm, thickness 3–16 mm, GOST 8509-93; equivalents to GB/T 706 and EN 10056
63×40–200×125 · t 4–16 · St3sp / 09G2S · GOST 8510
Unequal angle
Hot-rolled unequal angle 63×40–200×125 mm, thickness 4–16 mm, GOST 8510-86; equivalents to GB/T 706 and EN 10056
GOST 8510-86GOST 535-2005GOST 27772-2015GOST 19281-2014GB/T 706-2016EN 10056-1:2017St3spSt3psS245S25509G2SS345Q235BQ355B
Parameters
| Parameters | |
|---|---|
| Leg widths B×b | 63×40–200×125 mm |
| Flange thickness t | 4–16 mm |
| Length | 6–12 m, fixed length and multiples of fixed length |
| Rolling accuracy | V standard; A on project requirement |
| Steel grade | St3sp, St3ps, C245, C255, 09G2S, C345 |
| Surface | black uncoated hot-rolled steel |
Sizes and weight
| B×b, mm | t, mm | Weight, kg/m |
|---|---|---|
| 63×40 | 4 | 3.17 |
| 63×40 | 5 | 3.91 |
| 70×45 | 5 | 4.39 |
| 75×50 | 5 | 4.79 |
| 75×50 | 6 | 5.69 |
| 80×50 | 5 | 4.99 |
| 80×50 | 6 | 5.92 |
| 90×56 | 5.5 | 6.17 |
| 90×56 | 6 | 6.70 |
| 100×63 | 6 | 7.53 |
| 100×63 | 7 | 8.70 |
| 100×63 | 8 | 9.87 |
| 110×70 | 8 | 10.9 |
| 125×80 | 8 | 12.6 |
| 125×80 | 10 | 15.5 |
| 140×90 | 8 | 14.1 |
| 140×90 | 10 | 17.5 |
| 160×100 | 10 | 19.9 |
| 160×100 | 12 | 23.6 |
| 180×110 | 10 | 22.2 |
| 180×110 | 12 | 26.4 |
| 200×125 | 12 | 29.7 |
| 200×125 | 14 | 34.4 |
| 200×125 | 16 | 39.1 |
Description
An unequal angle is an L-shaped section with legs of different widths at a right angle. It is designated by the widths of the longer and shorter leg and the thickness: 100×63×8, 125×80×10. The wide leg is placed in the plane where the moment is greater, so this angle outperforms an equal angle where the load acts in one direction: in truss chords, opening frames and bearing brackets. It is rolled on section mills from square billets through grooved rolls; radii, weight per metre and rolling accuracy A or B are set by GOST 8510.
In GB/T 706 the unequal angle is designated by a pair of numbers in centimetres (6.3/4, 10/6.3, 12.5/8) and its size range largely matches GOST 8510. The bureau checks weight per metre against the table of the standard written in the specification, because each standard has its own corner radii. Steel grades: St3sp and St3ps to GOST 535, S245 and S255 to GOST 27772, 09G2S and S345 to GOST 19281 and GOST 27772; at mills in China, Q235B and Q355B with testing to the requirements of the specification.
During inspection at the mill we measure the width of both legs with callipers, thickness with a micrometer at the points set by the standard, and the angle between the legs with a protractor or a gauge; we check camber and twist along the length, length, and examine the surface for laps, scabs and cracks. We compare the mill test certificate (MTC), its heat number, chemical composition and mechanical properties, against the bundle tag; packing, piece count and loading are recorded with photographs in the inspection report.
Applications
- truss chords and diagonals
- opening frames and bearing brackets
- equipment beams and frames
- power transmission towers
- stairs, platforms and railings
- strengthening of existing structures
Packing and shipment
Bundles of 1–3 t strapped with steel band; the mill tag on the bundle carries steel grade, size, heat number, weight and bundle number.
Grade equivalents
| GOST | GB (China) | ASTM | EN | Note |
|---|---|---|---|---|
| St3sp5 / S245 | Q235B | A36 | S235JR | Impact toughness is specified at different temperatures: at −20 °C for St3sp5, at +20 °C for Q235B and S235JR. A cold-climate requirement is written into the specification separately. |
| S275 | Q275B | — | S275JR | Nearest equivalent by yield strength; chemical composition and scope of testing differ between the three standards. |
| 09G2S / S345 | Q355B | A572 Gr.50 | S355JR | Before GB/T 1591-2018 the grade was designated Q345B; certificates for earlier batches may still carry the old name. |
| S355 | Q355C | A572 Gr.50 | S355J0 | Nearest equivalent by yield strength of 355 MPa; impact test temperature and method are specific to each of the three standards. |
| — | Q355B | A992 Gr.50 | S355JR | A992 is a grade for wide-flange beams with an upper limit on yield strength. Nearest equivalent, not an exact match. |
| — | Q345P | A572 Gr.50 | S355GP | Sheet-pile grades. L4 and L5 to GOST 4781-85 are rolled from St3sp and St3ps; GOST has no dedicated sheet-pile grade. Nearest equivalent, not an exact match. |
Equivalents are the closest match, not identical: chemistry and tolerances differ between standards. The exact grade and standard are written into the contract.
Related items
No.5–40 · U / P · h 50–400 · St3sp5 / 09G2S · GOST 8240
Channel GOST 8240
Hot-rolled channel No. 5–40 to GOST 8240-97: U series with tapered flange faces and P series with parallel faces
Buyer questions
How to read a mill test certificate (MTC) for structural sections
Four blocks are checked in the certificate. Standard and grade: the same as written in the specification, not an equivalent. Heat number: matches the marking on the profile and the bundle tag. Heat chemistry: C, Si, Mn, P, S, and for Q355B also V, Nb, Ti, within the grade limits. Mechanical properties: yield strength, tensile strength, elongation and impact toughness at the temperature the grade requires. The bureau checks the certificate against the batch at the mill before shipment and attaches it to the inspection report.
How Q235B differs from St3sp5 and S245
All three have a yield strength of 235 MPa, which is why design calculations treat them as equivalents. The differences lie in test conditions and deoxidation: St3sp5 is impact-tested at −20 °C, Q235B at +20 °C; the suffix sp denotes killed steel, while Q235B to GB/T 700 is supplied rimmed (F) or killed (Z). If the project calls for St3sp5, the specification sets the degree of deoxidation and the test temperature; the mill performs the tests and enters the results in the certificate.
How the tonnage of a section order is calculated
From the theoretical weight per metre in the standard's table: weight per metre × length × number of pieces. The actual weight of a batch differs from the theoretical weight within the standard's weight tolerance, so the contract fixes which weight the batch is settled on: theoretical or actual by weighing. GB and GOST profiles of the same number have different theoretical weights; the specification is calculated to the standard written in it.
What is checked when structural sections are inspected at the mill
Section geometry: depth and flange width with callipers, web and flange thickness with a micrometer, at several points along the length. Shape: squareness of flanges, camber and twist along the length, length. Surface: laps, scabs, cracks, pits. Documents: the mill test certificate against the heat number on the marking and the tag. Packing, piece count and loading, with photographs in the inspection report.
What the minimum batch is and whether different profiles can be combined in one delivery
The batch is sized to your volume; send us the specification. A mill rolls each size to its rolling schedule, so the bureau matches the specification items against mill schedules, assembles the delivery from one or several mills and inspects every batch before shipment.
Price request
Send your specification and we will quote your batch
Steel pricing depends on grade, size, tonnage and delivery terms on the day of contract. A number on the page would be wrong by the time you read it.
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