Introducao
Um RFQ que diz GI coil, DX51D / SGCC / CS Type B OK parece flexivel. Em geral gera tres FOB incomparaveis. Uma usina cotiza EN 10346 DX51D+Z275. Outra preenche JIS G 3302 SGCC Z27. Uma terceira imprime ASTM A653 CS Type B G90 na proforma e dual-stamps DX51D na packing list. Espessura e largura podem bater; a janela de aceitacao nao.
Esta comparacao e para importadores que compram bobina galvanizada DX51D para telhado, dutos, revestimento e estoque de fabricacao geral. Nao e licenca para tratar EN 10346, JIS G 3302 e ASTM A653 como 100% equivalentes. Classes estruturais ou de alto yield como bobina galvanizada G550 ficam fora. Pedidos pre-pintados ainda precisam do substrato metalico na linha bobina PPGI.
O que os graus comerciais galvanizados congelam em EN, JIS e ASTM
Resumo tecnico rapido (resposta direta Featured Snippet): DX51D (EN 10346), SGCC (JIS G 3302) e ASTM A653 CS Type B sao designacoes comerciais de chapa galvanizada para conformado leve. Nao sao um SKU intercambiavel. Congele padrao dominante, grau do metal-base e codigo de revestimento (Z vs G) como tres campos antes de comparar cotacoes.
The break point is not which nickname sounds more international. It is which standard owns the mechanical table and which coating designation system owns the zinc mass. If the drawing cites EN 10346, a mill that only dual-stamps SGCC has not closed the order. If the drawing cites ASTM A653, a Z275 line without G90 (or the ordered ASTM A653M metric class) leaves the acceptance test open.
| Campo que o comprador deve congelar | Linguagem EN 10346 | Linguagem JIS G 3302 | Linguagem ASTM A653 / A653M |
|---|---|---|---|
| Commercial base metal | DX51D | SGCC | CS Type A / B / C |
| Coating chemistry | +Z (zinc) | Zinc under JIS mass table | Zinc-coated sheet |
| Coating mass code | Z100 / Z140 / Z275 (g/m2 both sides) | Z08 / Z12 / Z18 / Z27 style | G40 / G60 / G90 or metric Z |
| Typical duty | Light forming, lock seam | Asia-Pacific commercial sheet | North America commercial sheet |
| Do not treat as | Structural S280GD / S550GD | Structural SGC | Structural Grade 33/40/50 or SS |
Tres familias de normas, uma lista de precos: onde a equivalencia quebra
Commercial quality means suitable for ordinary bending and light forming inside each standard. It does not mean identical chemistry caps, identical yield ceilings, or identical bend-test language.
| Coluna de comparacao | DX51D+Z | SGCC | ASTM A653 CS Type B |
|---|---|---|---|
| Governing standard | EN 10346 | JIS G 3302 | ASTM A653/A653M |
| Commercial intent | Cold forming; ladder starts at DX51D | Commercial continuously galvanized | Commercial Steel Type B |
| Mechanical posture | Broad tensile band; confirm edition | Commercial tensile floor + JIS checks | Type letter freezes chemistry/forming |
| Coating unit system | Metric Z g/m2 both sides | Metric-style Z on JIS cards | Inch-pound G oz/ft2 and/or metric Z |
| Common false dual-stamp | ”DX51D = SGCC = CS” on one PI line | Same | Same |
| Safer RFQ rule | EN 10346 DX51D+Z### | JIS G 3302 SGCC + mass code | ASTM A653 CS Type B + G## or Z### |
Use the table as a scope gate, not as a chemistry substitute. Mill product cards and the ordered edition of each standard remain the referee. When a supplier says same commercial quality, ask which column on your RFQ they are volunteering to fail.
Codigos de revestimento ficam em outra linha que a letra do grau
A grade string without a coating code is incomplete. A coating code without a grade string is also incomplete. DX51D does not imply Z275. SGCC does not imply G90. CS Type B does not imply Z140.
| Necessidade do comprador | Escreva este par | Nao escreva so isto |
|---|---|---|
| EN outdoor zinc | EN 10346 DX51D+Z275 | ”DX51D GI coil” |
| JIS / Asia stock | JIS G 3302 SGCC Z27 (or project mass) | “SGCC equivalent to DX51D” |
| ASTM heavy zinc | ASTM A653 CS Type B G90 | ”CS coil, Z275 OK” |
| Light indoor zinc | One standard + one light mass class | ”Z80 / Z140 / G40 mix” |
| Painted roofing substrate | Grade + metallic mass + paint on bobina PPGI RFQ | RAL color alone |
G90 and Z275 often sit near the same zinc mass (~275 g/m2 total both sides; GalvInfo uses 1.00 oz/ft2 = 305 g/m2). Sitting near is not identity. ASTM A653 G90 is an oz/ft2 class with triple-spot and single-spot gates. EN 10346 Z275 is a metric mass class. If the drawing is ASTM, freeze G90 (or the ordered ASTM A653M Z class). If the drawing is EN, freeze Z275. Do not let a dual-stamp erase the test method.
This article does not reopen the Z80 / Z140 / Z275 mass tear-down. When the only open question is zinc grams, use the coating-mass guide. When the open question is which commercial standard owns the coil, stay on this cross-reference.
Janelas quimicas e mecanicas que o comprador deve comparar
Commercial grades look close until the RFQ forces the mill to print numbers. The 6D view below is the minimum comparison set before anyone claims equivalence.
| Dimensao 6D | O que congelar no RFQ | Por que DX51D / SGCC / CS Type B ainda divergem |
|---|---|---|
| Chemical limits | C, Mn, P, S (and edition extras) | Each standard publishes its own commercial chemistry table |
| Mechanical thresholds | Yield/proof posture, tensile band, elongation by thickness | Forming ladders are not written the same across EN / JIS / ASTM |
| Dimensional tolerances | Thickness basis, width, flatness, EN 10143 / ASTM A924 | Tolerance class is independent of commercial nicknames |
| Surface / coating | Spangle, passivation, oil, designation, equal vs differential | Coating mass is separate from DX51D / SGCC / CS letters |
| Seaworthy packing | VCI, edge guards, eye-to-sky / eye-to-wall, straps, coil ID | Packing claims do not prove which standard was coated |
| MTC governance | EN 10204 3.1, heat, coating-mass method, mechanicals | Dual-stamp text without ordered standard is a documentation gap |
Treat published typical chemistry rows on distributor pages as cautious. Confirm the ordered edition. For EN 10346 DX51D-type commercial coil, mill tables buyers commonly see keep carbon low for forming and list a wide tensile band suitable for bending rather than structural design. For JIS G 3302 SGCC, commercial tensile floors and bend checks follow the JIS card the mill cites. For ASTM A653 CS Type B, the Type letter is part of the order—Type A / B / C are not free synonyms inside one PO.
If the part needs deep drawing, step up the forming ladder inside the same standard family (for example DX52D / DX53D under EN, or the corresponding ASTM FS / DDS classes). Do not upgrade a failed DX51D bend by swapping in an unverified SGCC dual-stamp.
Hard structural duty is a different RFQ. bobina galvanizada G550 and EN structural SxxxGD classes are yield-driven. They are not commercial DX51D / SGCC alternates.
Checagem de primeira mao: etiquetas, MTC e fotos de embalagem
On recent Shandong export lots, the mismatch rarely starts at the port. It starts when the PI says DX51D / SGCC interchangeable, the stencil says SGCC, and the EN 10204 3.1 MTC prints a coating mass without naming the ordered EN grade string. Buyers who only check thickness and shine load a coil that their project engineer cannot accept against an EN drawing.
| Checagem antes de estivar | Sinal de aprovacao | Sinal de hold |
|---|---|---|
| Stencil vs PI | Same standard + grade + coating code | ”DX51D/SGCC” on PI, only SGCC on stencil |
| MTC grade line | Ordered standard printed in full | Dual-stamp paragraph with no ordered edition |
| Coating result | Mass + method matching Z or G class | Micron gun photo only |
| Mechanicals | Values inside ordered commercial table | Blank elongation / wrong Type letter |
| Heat identity | Heat on MTC = tag and packing list | Mixed heats under one nickname |
| Packing mark | Grade and coating readable after wrap | Generic “GI COIL” kraft only |
Third-party inspection helps when coupons for weigh-strip-weigh and tensile checks are named in the order. pratica de documentacao de usina EN 10204 3.1 is the paper trail; PSI is the coil-side check. Sheet product pages such as chapa galvanizada DX51D still need the same standard freeze when the mill offers cut lengths instead of coil.
Lista RFQ que mantém os tres sistemas comparaveis
Paste this block into the RFQ. Keep one primary standard. List alternates only if engineering signed them.
- Product: continuously hot-dip galvanized steel coil (not batch HDG after fabrication).
- Primary standard / grade: choose one — EN 10346 DX51D+Z, or JIS G 3302 SGCC, or ASTM A653 CS Type B.
- Accepted alternates: none, unless named with the same coating mass class and signed by engineering.
- Coating designation: one code only (Z140, Z275, G60, G90, or the project code). No “Z275 / G90 / Z27 same” slash line.
- Coating test: minimum total both sides by the method in the ordered standard; weigh-strip-weigh referee allowed.
- Surface: spangle, Cr-free passivation, oiled or dry as named.
- Size: thickness basis x width x coil ID; tolerance standard EN 10143 or ASTM A924 as applicable.
- Documents: EN 10204 3.1 MTC with heat number, chemistry, mechanicals, coating mass, and ordered standard string.
- Inspection: TPI coupons allowed for coating mass and tensile/elongation.
- Packing / lot: VCI + edge guards + named strap count; 1 x 20GP (25-28 MT); dispatch 7-15 days for standard sizes.
If the mill answers with DX51D equivalent SGCC equivalent CS Type B, the quote is not comparable. Send the block back with one primary standard before anyone prices the coil family.
Conclusao
DX51D, SGCC, and ASTM A653 CS Type B are commercial galvanized designations under three different standard systems. They can serve similar light-forming duties, but they are not 100% equivalent mill stock. Freeze the governing standard, the base-metal grade, and the coating code as separate fields. Read those fields on the stencil and the EN 10204 3.1 MTC before the coil is stuffed. Use structural or deep-drawing grades only when the drawing asks for them—not as silent substitutes for a commercial cross-reference.
Planejando um pedido ou precisa de verificacao tecnica?
Se voce compra bobina de aco galvanizado sob EN 10346 DX51D, JIS G 3302 SGCC ou ASTM A653 CS Type B:
- Cotacao tecnica rapida: pedidos-teste a partir de 1 x 20GP (25-28 MT) com 7-15 days de despacho. Envie grau, revestimento, espessura x largura e quantidade pelo nosso Formulario RFQ online.
- Garantia da qualidade: cada pedido com EN 10204 3.1 MTC e rastreabilidade de heat. SGS, BV, TUV sao bem-vindos. Compradores brasileiros devem exigir cotacao comparavel e especificacao completa; requisitos MTC incoerentes nascem de RFQ incompleto.
- Consultas urgentes: WhatsApp +86 151 5311 2221.
