If you have ever opened a steel grade equivalents chart and seen ASTM A36, EN S235JR, JIS SS400, and GB Q235 lined up in one row labeled “equivalent,” you already know how dangerous that table is. The four grades are similar enough to be interchangeable for many structural jobs, and different enough that substituting one without checking can fail an inspection, a weld procedure, or a structural calculation. Treat the chart as a starting point for conversation, not a license to buy the cheapest option and call it the same steel.
This guide gives procurement managers a practical steel grade comparison chart across the four standards that dominate international buying – ASTM vs EN vs JIS vs GB – covering carbon structural steel, HSLA plate, stainless, galvanized coil, pipe, and rebar: real grade numbers, minimum yield and tensile strengths in MPa, the impact-testing differences most charts omit, and honest caveats about what “equivalent” means. We supply steel to all four systems from Yihang Metal (www.yihangmetal.com), so the guidance below comes from real RFQs.
Why Grade Equivalence Confuses Importers (and Why “Equivalent” Is Never Exact)
A single “grade” is rarely a single product. EN S235 is really three products – S235JR, S235J0, and S235J2 – that differ only in the Charpy impact requirement (27 J at 20°C, 0°C, or -20°C). GB Q235 is four products (Q235A, B, C, D) with the same split; Q235A has no impact requirement. ASTM A36 is nominally one product, but impact testing is added only as a supplementary requirement. A chart that shows “A36 = Q235B” is silently picking one sub-grade and ignoring the others.
The second reason is that the four standards guarantee different properties. JIS SS400 is designated by tensile strength – the “400” is 400 N/mm² minimum tensile – and certifies no minimum yield (typical around 245 MPa, but not guaranteed). ASTM and GB grade names start from yield strength (A36 = 36 ksi = 250 MPa; Q235 = 235 MPa), while EN names yield with an impact suffix. The third reason is chemistry: each standard caps carbon, phosphorus, and sulfur differently, changing weldability and formability – invisible on any chart that stops at yield strength.
The honest rule for substitution: an “equivalent” grade is one whose certified minimum properties cover the requirements of the standard your design references – not one with a similar name or a row on a chart. The chart saves you time; the certificate proves the substitution.
How Each Standard System Works: ASTM, EN, JIS, GB – A Quick Primer
- ASTM – the US system, widely used in the Middle East, Africa, and Latin America. Grades are often named after yield in ksi (A36 = 36 ksi); metric versions carry an “M” suffix (A36M). Tolerances come from companion standards: A6/A6M for structural shapes and plate, A20/A20M for pressure-vessel plate.
- EN – the metric system used across the EU and most of the world outside North America. Structural grades follow EN 10025-2 (S235, S275, S355) with impact sub-grades JR/J0/J2 (27 J at 20°C / 0°C / -20°C), and EN 10204 defines the inspection documents (2.2, 3.1, 3.2) now treated as the certificate standard worldwide.
- JIS – the Japanese system (G3101, G3106, G3302, G3444, G3112). Many designations are tensile-based (SS400 = 400 N/mm² tensile), which surprises buyers used to yield-based names. Tolerances follow standards such as JIS G3193.
- GB – the Chinese national standard. GB standard steel is the norm for domestic production and much of Chinese exports: structural carbon is GB/T 700 (Q235), HSLA is GB/T 1591 (Q355, renamed from Q345 in 2018), plates are GB/T 3274, tolerances per GB/T 709. “GB/T” means recommended; “GB” alone is mandatory.
Carbon Structural Steel Equivalents (A36, S235JR, SS400, Q235)
The most-requested cross-reference is the general structural workhorse group: A36 (ASTM), S235JR (EN 10025-2), SS400 (JIS G3101), and Q235 (GB/T 700), with minimums as the standards state them:
| Grade (standard) | Min yield, t ≤ 16 mm | Min tensile (UTS) | Impact requirement |
|---|---|---|---|
| A36 (ASTM A36/A36M) | 250 MPa (36 ksi) | 400-550 MPa | None as standard |
| S235JR (EN 10025-2) | 235 MPa | 360-510 MPa | 27 J at 20°C (JR); J2 at -20°C |
| SS400 (JIS G3101) | ~245 MPa typical, not guaranteed | 400-510 MPa | None |
| Q235 (GB/T 700) | 235 MPa | 370-500 MPa | B: 27 J at 20°C; D: 27 J at -20°C |
The practical reading: Q235 vs A36 is the most common substitution question. They are close for general structural work but not identical – A36 guarantees a higher yield (250 vs 235 MPa), while Q235B carries a Charpy requirement plain A36 does not guarantee, making Q235B the safer buy where documented toughness matters. The S235JR equivalent of Q235 is the most defensible swap: both 235 MPa yield, both 27 J at 20°C, overlapping tensile bands. The SS400 equivalent of Q235 is the weakest link: it certifies tensile but not yield – if your calculation depends on certified yield, ask the mill to report yield as an additional test. See our A36 vs Q355 comparison for importers for the two most common grades in this family.
High-Strength Low-Alloy Equivalents (A572 Gr50, S355JR, SM490, Q355)
When the design steps up to higher strength per tonne, the group becomes A572 Gr50 (ASTM A572/A572M), S355 (EN 10025-2), SM490 (JIS G3106), and Q355 (GB/T 1591):
| Grade (standard) | Min yield, t ≤ 16 mm | Min tensile (UTS) | Impact requirement |
|---|---|---|---|
| A572 Gr50 (ASTM A572) | 345 MPa (50 ksi) | 450 MPa | None as standard |
| S355JR (EN 10025-2) | 355 MPa | 470-630 MPa | 27 J at 20°C (JR); J2 at -20°C |
| SM490 (JIS G3106) | 325 MPa | 490-610 MPa | A: none; B/C: 27 J at 0°C |
| Q355 (GB/T 1591) | 355 MPa | 470-630 MPa | B: 34 J at 20°C; D: 34 J at -20°C |
S355 is the European workhorse for cranes, bridges, and machinery; Q355 is its Chinese counterpart with nearly identical numbers. The trap is thickness derating: EN and GB reduce certified yield as thickness grows (S355/Q355 fall to 345 MPa above 16 mm), while A572 Gr50 holds 345 MPa to its 100 mm limit – so substituting A572 Gr50 for S355 at 30 mm plate gives a stronger plate, which must be rechecked, not assumed. SM490’s 325 MPa yield sits below the others despite its 490 MPa tensile name. For the plate decision, our A36 vs A572 Grade 50 buying guide covers the trade-offs.
Carbon Steel Plate and Sheet Equivalents (A283, S275JR, SS400, Q235B)
For hot-rolled plate and sheet for tanks and general fabrication, the group is A283 (ASTM A283/A283M), S275JR (EN 10025-2), SS400 (JIS G3101), and Q235B (GB/T 3274 plate). A283 Gr C guarantees 380-515 MPa tensile and Gr D 415-550 MPa, with no specified minimum yield – the same tensile-based logic as SS400. S275JR guarantees 275 MPa yield (t ≤ 16 mm) and 410-560 MPa tensile, a step above Q235B; Q235B plate guarantees 235 MPa yield and 370-500 MPa tensile with 27 J at 20°C impact.
Three plate-specific checks matter. First, thickness-dependent yield: EN and GB derate yield as thickness grows, while A283 has no yield claim at all. Second, tolerances: plate thickness tolerance comes from ASTM A20/A6M, EN 10029 (Classes A, B, C), JIS G3193, or GB/T 709 – and because you pay by theoretical weight, a plate rolled to the loose end of a mill’s under-tolerance is a lighter shipment and a “cheaper” quote that is actually less steel – ask for the tolerance class on the quotation. Third, low-temperature service: below -20°C, use Q235D, S235J2/S275J2, or A36 with A673 impact testing.
Stainless Steel Equivalents (304/304L, 316/316L, 430, 201)
Stainless cross-references are more reliable than carbon ones because chemistry, not just strength, defines the grade. The mapping across GB/T 3280 (GB), JIS G4304 (JIS), EN 10088-2 (EN), and ASTM A240/A276 (ASTM):
| GB designation | JIS | EN 10088-2 | ASTM | Min yield / tensile (annealed) |
|---|---|---|---|---|
| 06Cr19Ni10 | SUS304 | X5CrNi18-10 (1.4301) | 304 | 205 / 515 MPa |
| 022Cr19Ni10 | SUS304L | X2CrNi18-9 (1.4307) | 304L | 170 / 485 MPa |
| 06Cr17Ni12Mo2 | SUS316 | X5CrNiMo17-12-2 (1.4401) | 316 | 205 / 515 MPa |
| 022Cr17Ni12Mo2 | SUS316L | X2CrNiMo17-12-2 (1.4404) | 316L | 170 / 485 MPa |
| 10Cr17 | SUS430 | X6Cr17 (1.4016) | 430 | 205 / 450 MPa |
| 12Cr17Mn6Ni5N | SUS201 | X12CrMnNiN17-7-5 (1.4372) | 201 | 310 / 655 MPa |
Two warnings. First, 304L vs 304 and 316L vs 316 are not cosmetic choices: the “L” is a guaranteed max 0.03% carbon that prevents chromium-carbide precipitation in the weld heat-affected zone – for welded tanks and piping, specify the L grades and verify carbon on the MTC. Second, 201 is the most abused cross-reference in the market: nickel-reduced 201 (and non-standard “J4”) substitutes manganese for nickel to cut cost and fails where 304’s corrosion resistance is required. 201 can be a legitimate economy choice for architectural service – never substitute it for 304 without confirming the environment.
Galvanized Coil Equivalents (DX51D, SGCC, CS-B, SGHC)
Galvanized coil cross-references by both base metal and coating, and buyers regularly mix the two. The families are DX51D (EN 10346), SGCC (JIS G3302), CS-B (ASTM A653/A653M), and SGHC (JIS G3302, hot-rolled base); Chinese supply is typically specified to GB/T 2518, which includes DX51D+Z alongside its own SGC-series grades:
- DX51D – “D” for forming; EN 10346 sets no mandatory strength values (agreed at order), typical tensile around 270-500 MPa. The coating class is the real spec: Z100 to Z450 (g/m² total, both sides), plus ZF (galvannealed) and AZ (aluminum-zinc).
- SGCC – general-use hot-dip galvanized sheet; JIS G3302 guarantees minimum tensile 270 N/mm² (thickness ≥ 0.25 mm); coatings designated by thickness (Z12-Z27).
- CS-B – Commercial Steel B per ASTM A653; no guaranteed strength (qualified by bend test); coatings G30-G235 in oz/ft² (G60 and G90 the common orders).
- SGHC – hot-dip galvanized with a hot-rolled base for heavier use; minimum tensile 270 N/mm².
Convert coating designations before comparing prices – the single most common steel standard cross reference mistake in coated coil buying:
| EN 10346 | ASTM A653 | JIS G3302 (approx.) | Coating mass (total, both sides) |
|---|---|---|---|
| Z90 | G30 | Z12 | ~90 g/m² |
| Z180 | G60 | Z18 | ~180 g/m² |
| Z275 | G90 | Z27 | ~275 g/m² |
| Z350 / Z450 | G115+ / special | Special order | 350 / 450 g/m² |
A “cheaper” galvanized quote is frequently a thinner coating quoted in a different designation system – Z90 vs Z275 is roughly three times less zinc and a much shorter service life. Always state the coating class and require the coating weight on the certificate.
Pipe and Tube Equivalents (A53, S275J0H, STK400, Q235B)
Pipe cross-referencing carries an extra trap: you must know whether the product is structural (strength is everything) or pressure-service (strength plus hydrostatic and NDE requirements). The common structural group is A53 Gr B (ASTM A53), S275J0H (EN 10210-1, hot-finished hollow sections), STK400 (JIS G3444), and Q235B (GB/T 3091 welded / GB/T 8162 seamless):
- A53 Gr B – the ASTM workhorse for welded and seamless carbon pipe, black or galvanized; min yield 240 MPa (35 ksi), min tensile 415 MPa (60 ksi); covers structural and low-pressure service.
- S275J0H – EN 10210-1 hot-finished structural hollow section; min yield 275 MPa (t ≤ 16 mm), tensile 410-560 MPa, with 27 J at 0°C guaranteed by the J0 suffix.
- STK400 – JIS G3444 tube for general structural purposes; min yield 245 MPa, min tensile 400 MPa (tensile-based, as usual for JIS); STKR400 is the ERW version.
- Q235B – GB/T 3091 welded pipe and GB/T 8162 seamless structural tube; yield 235 MPa, tensile 370-500 MPa; the default Chinese pipe grade, often dual-specified with A53 Gr B for export.
Before treating these as interchangeable, verify whether the spec is structural or pressure (EN 10210 is structural only – for pressure use EN 10216/10217 or GB/T 8163); the testing regime (hydrostatic, flattening, and NDE requirements differ by standard); and the dimension basis – NPS/OD and schedule is not the same as metric OD x WT, and schedule 40 is not the same wall as every GB series size. For welded structures, EN 10210 is qualified to its own section geometry – swapping in ERW tube without rechecking member design and welding procedure is a classic site rejection.
Rebar Equivalents (A615 Gr60, B500B, SD390, HRB400)
Rebar is where equivalence claims do the most damage, because it is a certified structural material with bar-marking and seismic implications. The group most charts show is A615 Gr60 (ASTM), B500B (EN 10080 / BS 4449), SD390 (JIS G3112), and HRB400 (GB/T 1499.2):
| Grade (standard) | Min yield | Min tensile | Elongation | Notes |
|---|---|---|---|---|
| A615 Gr60 (ASTM A615/A615M) | 420 MPa (60 ksi) | 620 MPa (90 ksi) | 7-9% by bar size | Carbon rebar; not optimized for welding or seismic |
| B500B (EN 10080) | 500 MPa (500-550 range) | ≥ 540 MPa | Agt ≥ 5% | Weldable per Eurocode 2; CE-marked for EU projects |
| SD390 (JIS G3112) | 390 MPa (390-510 range) | ≥ 560 MPa | ≥ 16% (size-dependent) | Common Japanese structural rebar |
| HRB400 (GB/T 1499.2) | 400 MPa (400-540 range) | ≥ 540 MPa | A ≥ 16% | China’s default structural rebar; HRB500 also common |
The honest caveat is unavoidable: B500B at 500 MPa is not a strength match for HRB400 or Grade 60 – it aligns with HRB500, so a design written for B500B cannot be satisfied with HRB400 no matter what the chart says. The defensible swaps are A615 Gr60 / SD390 / HRB400 (390-420 MPa band) and A615 Gr80 / B500B / HRB500 / SD490 (500 MPa band). Two further checks apply to every substitution: welding – welded splices or seismic ductility require ASTM A706, not A615; and bar marking – every legitimate bar carries the standard, grade, and mill mark in its deformation pattern, so a wrong-standard bar is catchable at receipt. For the full picture, our rebar sourcing guide covers A615 vs A706 and coatings.
The 4 Things to Verify When Substituting a Grade
When a supplier offers “equivalent” material, verify these four things against the governing standard – they are the entire difference between a legitimate substitution and a site rejection:
- 1. Chemistry. Compare actual limits, not just names: carbon (A36 allows up to 0.26% C, Q235B caps at 0.20%), phosphorus, sulfur, and residuals like Cr, Ni, Cu – plus the carbon equivalent (CEV) for welding.
- 2. Mechanicals. Match certified yield, tensile, and elongation minimums – and above all the impact test: which energy at which temperature (27 J at 20°C and 34 J at -20°C are different materials in cold service). Check the yield-to-tensile ratio for seismic designs.
- 3. Tolerances and dimensions. Thickness and width tolerances come from different systems (ASTM A20, EN 10029, JIS G3193, GB/T 709) and differ by class – they change your theoretical-weight tonnage and the section properties your calculation assumed.
- 4. Testing and certification. Confirm the test basis (ASTM A370/E8 vs ISO 6892-1 vs GB/T 228), whether testing is per heat or per lot, and the certificate type – EN 10204 3.1 minimum, 3.2 (third-party witnessed) for project-critical or seismic material. Our EN 10204 certificate guide explains what each type proves.
If the certificate cannot be reconciled with the governing standard – wrong test method, wrong impact temperature, chemistry outside limits – the substitution does not exist, regardless of the grade name. Grade names are labels; certificates are evidence.
How to Request Cross-Referenced Material in an RFQ
A cross-referenced RFQ names one governing standard and treats the others as information. The formula that returns comparable quotes:
- Governing spec first: “S275JR per EN 10025-2” or “A572 Gr50 per ASTM A572/A572M” – never “S275/A572 equivalent” as the whole specification.
- Cross-reference for documentation: state which other grades are acceptable if the mill’s schedule favors them: “S275JR per EN 10025-2, Q235B per GB/T 700 acceptable, cross-referenced on the 3.1 MTC.”
- Dimensions and tolerance standard: thickness, width, length, and tolerance class (e.g., “EN 10029 Class A”) – tolerances drive tonnage and fit.
- Delivery condition and finish: hot-rolled, normalized (for high-strength plate), pickled, or galvanized with the coating class (Z275, G90).
- Testing and certificate: test method (ISO 6892-1 or ASTM E8), Charpy energy and temperature, EN 10204 3.1 minimum, 3.2 witnessed if required.
- End use, quantity, and Incoterm: application in one line, quantity in tonnes, Incoterm (FOB, CIF, DAP).
A complete cross-referenced RFQ line reads: “Hot-rolled structural plate, 12 mm x 2000 mm x 6000 mm, 40 t, S275JR per EN 10025-2 (Q235B per GB/T 700 acceptable, cross-referenced on MTC), tolerance EN 10029 Class A, tested per ISO 6892-1 with Charpy 27 J at 20°C, EN 10204 3.1 MTC, FOB Shanghai.” That line returns three comparable quotes; “S275 or equivalent plate, 12 mm” returns three different products. For the full RFQ format, see our steel quote request template.
How Yihang Metal Supplies Grades to Any Standard
We supply carbon steel, HSLA plate, stainless, galvanized coil, pipe, and rebar to all four standard systems – ASTM, EN, JIS, and GB – from mills we qualify per product family. What that means for a buyer comparing grades across standards:
- Governing-standard quoting: we quote against the standard you specify and state any cross-reference explicitly – never as a surprise substitution at dispatch.
- Dual certification: where chemistry and mechanicals allow, material can be tested to one standard and certified against two (e.g., tested per ISO 6892-1, documented to both GB/T 700 and EN 10025-2).
- Mill selection by family: we use mills whose tolerance classes and impact-testing practice match the target standard – a Q235B plate mill is not automatically the right source for an S355J2+N order.
- EN 10204 3.1 MTCs as standard, with 3.2 witnessed certificates and independent inspection (SGS, BV, TUV) for project-critical or seismic programs.
- Sea-worthy export packing and full shipping documentation – see our export packing checklist for what we ship to.
Because we quote and certify across all four systems side by side, we can give you a like-for-like cost comparison at the exact grade, tolerance class, and certificate level each project needs.
Comparing steel grades across standards and not sure which cross-reference your project can accept? Send us your governing standard, grade, dimensions, quantity, and destination country. The team at Yihang Metal (www.yihangmetal.com) will confirm the correct cross-reference, flag any chemistry, impact, or tolerance gaps, and return a quotation with full EN 10204 documentation within 24 hours. Request your cross-referenced quote today and buy steel that matches the certificate – not just the name.