No.10–60 · h 100–600 · St3sp5 / C245 / 09G2S · GOST 8239
I-beam GOST 8239
Hot-rolled I-beam with tapered inner flange faces, No. 10–60 to GOST 8239-89; nearest equivalents are IPN and GB/T 706
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
GOST 8240-97GOST 535-2005GOST 27772-2015GOST 19281-2014GB/T 706-2016EN 10279:2000St3sp5St3ps5S24509G2SS345Q235BQ355B
Parameters
| Parameters | |
|---|---|
| Profile number | 5–40 |
| Series | U with tapered flanges, P with parallel flanges |
| Depth h | 50–400 mm |
| Flange width b | 32–115 mm |
| Web thickness s | 4.4–8.0 mm |
| Length | 6–12 m, fixed length and multiples of fixed length |
| Steel grade | St3sp5, St3ps5, C245, 09G2S, C345 |
Sizes and weight
| No. | h, mm | b, mm | s, mm | t, mm | Weight, kg/m |
|---|---|---|---|---|---|
| 5 | 50 | 32 | 4.4 | 7.0 | 4.84 |
| 6.5 | 65 | 36 | 4.4 | 7.2 | 5.90 |
| 8 | 80 | 40 | 4.5 | 7.4 | 7.05 |
| 10 | 100 | 46 | 4.5 | 7.6 | 8.59 |
| 12 | 120 | 52 | 4.8 | 7.8 | 10.4 |
| 14 | 140 | 58 | 4.9 | 8.1 | 12.3 |
| 16 | 160 | 64 | 5.0 | 8.4 | 14.2 |
| 18 | 180 | 70 | 5.1 | 8.7 | 16.3 |
| 20 | 200 | 76 | 5.2 | 9.0 | 18.4 |
| 22 | 220 | 82 | 5.4 | 9.5 | 21.0 |
| 24 | 240 | 90 | 5.6 | 10.0 | 24.0 |
| 27 | 270 | 95 | 6.0 | 10.5 | 27.7 |
| 30 | 300 | 100 | 6.5 | 11.0 | 31.8 |
| 33 | 330 | 105 | 7.0 | 11.7 | 36.5 |
| 36 | 360 | 110 | 7.5 | 12.6 | 41.9 |
| 40 | 400 | 115 | 8.0 | 13.5 | 48.3 |
Description
A channel is a C-shaped section with a web and two flanges on one side. The number equals the depth in centimetres; the GOST 8240 range runs from No. 5 to No. 40. The U series has tapered inner flange faces, the P series has parallel faces; depth, flange width, thicknesses and weight per metre of U and P profiles of the same number are identical, the difference lies in the flange shape. Channels are rolled on section mills from blooms or square billets through grooved rolls; rolling accuracy is A (high) or B (standard).
The channel from mills in China to GB/T 706 is designated 5#–40# and differs from GOST in section: 10# has a 48 mm flange, a 5.3 mm web and a weight of 10.0 kg/m against 46 mm, 4.5 mm and 8.59 kg/m for No. 10 to GOST 8240. Substituting one for the other without recalculation changes both the tonnage and the load-bearing capacity, so the bureau either finds a mill with roll passes for GOST or agrees the substitution with the designer. Grades: St3sp5 and St3ps5 to GOST 535, S245 and S345 to GOST 27772, 09G2S to GOST 19281; at the mill in China, Q235B and Q355B with testing to the requirements of the specification.
During inspection at the mill we measure depth and flange width with callipers, web and flange thickness with a micrometer at several points along the length; for the P series we check flange parallelism, for both series camber, twist and length. We 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 marking on the flange and the bundle tag; packing and loading are recorded with photographs in the inspection report.
Applications
- purlins and girders of frames
- steel-framed hangars and light buildings
- stairs, platforms and railings
- equipment frames and supports
- embedded parts and opening frames
- trailer and body frames
Packing and shipment
Bundles up to 5 t strapped with steel band at three points; paint marking on the flange: mill, steel grade, profile number, heat number; the bundle tag duplicates the certificate.
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
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
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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