Q235 Steel Grades
Q235 belongs to GB/T 700:2006, the Chinese national standard for carbon structural steels, and the way the name itself is assembled is set by a second national standard. This page is about what the designation fixes, what the quality letter at the end of it decides, which GB document answers which question, and why no chemistry table appears here.
- Designation
- Q235
- Family
- Non-alloy steel
GB/T 700:2006
The standard that carries the grade
GB/T 221:2008
The standard that sets how the name is written
No online reading
What the portal offers for the grade standard
GB/T 3274:2017
The product standard behind a flat order
The Q235B designation taken apart: the yield strength letter, the minimum yield value in megapascals, and the quality letter that decides what is tested.
What Q235 Names
Q235 is a name out of GB/T 700:2006, the Chinese national standard for carbon structural steels. How that name is assembled is the business of a second document, GB/T 221:2008, which is the national standard for writing an iron and steel product designation at all. Two standards, two jobs: one fixes what the steel has to be, the other fixes how its name is put together.
A designation is not a product. Q235 says nothing about whether the steel arrives as a coil, a plate, a section or a bar; nothing about the rolling route it took; nothing about the surface it arrives with. Each of those is a separate field of an order governed by a separate document, and the table further down this page says which one answers which question.
The last character of the name is where most of the trouble lives. Q235 written without its quality letter is an incomplete name, and the two sections that follow set out what the letter decides, and why this page prints no table of what each one requires.
Reading the Designation
How a GB designation is assembled is itself a published standard. GB/T 221:2008, Notations for designation of iron and steel, was issued on 2008-08-05 and took effect on 2009-04-01, and the Chinese national standards full-text portal lists it as current with both online preview and download available. So the question of what the letter Q expresses, what the number expresses and what the final letter expresses has one authoritative answer, and reading it costs nothing.
This page does not paraphrase that answer. The rule has not been read out of the portal's own text and recorded here, and a designation system restated from memory or off a trading site is exactly the kind of thing that circulates for years without anyone checking it against the document. What can be said without that reading is what the name does commercially: it identifies the steel, it is the field the certificate gets written against, and every character in it carries load.
That last point is not pedantry. Q235 and Q235B are two different entries in the grade field of a purchase order. A factory receiving the first has been left to settle something that the second one settles.
What the Quality Letter Decides
The letter at the end of a carbon structural designation selects the acceptance requirements the factory has to meet and then report. It is not a finish, not a surface condition and not a size. It is the part of the name that decides what gets tested and what the certificate has to carry back.
Which letters GB/T 700:2006 defines, and what each of them requires, is in that standard, and neither appears on this page. The reason is the next section and it is not an oversight. A requirement table lifted from somewhere else, carrying no edition and no clause number, is worth less than the sentence you are reading, and a page that prints one has made itself impossible to check.
What is worth stating is the consequence for an order. A grade field reading Q235 leaves the letter open, and whoever makes the steel closes it. A grade field reading Q235B has closed it, and the certificate then has something to be compared against. Which letter a part actually needs is a question for whoever owns the specification, answered against the edition of GB/T 700:2006 the order is accepted under.
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Which GB Document Answers Which Question
A GB order for a flat product is written across several standards at once, and the commonest mistake is to name one of them and assume the rest follow. The table sets out which document settles which question, and what the standards platform said about each of them on 2026-09-20.
| Document | What it settles | What the portal showed |
|---|---|---|
| GB/T 221:2008 | How an iron and steel product designation is written | Current, with online preview and download |
| GB/T 700:2006 | The carbon structural grades and their requirements | Current; no online preview and no download offered |
| GB/T 1591:2018 | The high strength low alloy structural grades - a separate family, not a higher rung of this one | Current, with online preview and download; it fully replaced GB/T 1591-2008 |
| GB/T 3274:2017 | The hot rolled plates, sheets and strips of both families: the product form | Current, with online preview and download; it fully replaced GB/T 912-2008 and GB/T 3274-2007 |
| GB/T 709:2019 | Dimensions, shape, weight and permissible deviations of hot rolled flat products | Current, with online preview and download; the download step asks for a verification code |
| GB/T 34560.2:2017 | Technical delivery conditions for structural steels for general purposes | Current, and a separate standard: it has not replaced the grade standard above it |
| Project 20251168-T-605 | A registered revision project, not a standard | Notified in 2025, with nothing published by 2026-09-20 |
Two readings come out of that table. The first is that the family boundary is a standard boundary: the carbon structural grades and the high strength low alloy grades sit in different documents, with different tables and different certificates, and a designation from one is not a stronger version of a designation from the other.
The second is the row that looks different from all the others. Five of these documents can be opened on the portal for nothing. One cannot, and it happens to be the one that carries the grade.
Why This Page Prints No Property Table
Search this designation and chemistry and mechanical tables turn up everywhere, all of them agreeing with each other to a degree that ought to raise an eyebrow. Here is what the record actually shows.
On 2026-09-20 the Chinese national standards full-text portal listed GB/T 700:2006, Carbon structural steels, as current, issued 2006-11-01 and effective 2007-02-01. That page carried no online preview button and no download button. In their place it carried a notice: the standard adopts standards of international bodies such as ISO and IEC, and because of copyright the system does not provide an online reading service for it.
On the same portal, on the same day, GB/T 221:2008, GB/T 1591:2018, GB/T 3274:2017 and GB/T 709:2019 all offered preview and download. So the grade standard is the exception, not the rule, and every property table for this family circulating on supplier pages came from somewhere other than the source of record. A reader has no way to check one against the standard, and neither has the page printing it.
Two further facts belong here, because both are misreported. GB/T 700:2006 is still current: the revision project 20251168-T-605 is registered on the standards platform and would fold this standard together with several others into a general-purpose delivery standard, but by 2026-09-20 it had published nothing. And GB/T 34560.2:2017 exists alongside the grade standard rather than in place of it. Neither fact changes what goes on your order. Both change what to make of a page announcing that the standard has moved on.
What a Cross-Standard Question Needs First
Can this grade answer a drawing written in another standard system is the question this designation attracts most, and it cannot be answered from two names. Eight things have to be on the table first, and they are ordinary fields rather than research. Once they are written down the question usually answers itself; until they are, no answer given is worth keeping.
- The complete designation on both sidesWith the quality letter, and with whatever letters the other system puts after its own number. A name with a character missing is not a specification, and it is the commonest reason a comparison ends up comparing two different things.
- The standard and edition behind each nameNot the system, the document. GB/T 700:2006 on this side; on the other side, whichever document the drawing actually names, in the edition the order would be accepted against.
- The product form each standard reachesA specification can only describe the forms its own scope names. Where one side covers a form the other does not, the comparison has already produced its answer and the rest of the checking is confirmation.
- The thickness band the part sits inRequirements in both systems move with thickness, and a band that crosses a step in one standard but not in the other is where a comparison quietly stops holding.
- The delivery and surface conditionAs it will actually be delivered, in plain words. It travels with the ordering route rather than with the grade name, so it survives a change of designation without being changed itself, which is how it gets forgotten.
- The test basis behind every value comparedWhere the sample was taken, in which direction it was tested, and under what condition. Two tables can print the same number and mean two different checks, and a comparison that ignores the basis is comparing the printing rather than the steel.
- What the certificate will sayOne standard with its edition, one grade, and the measured results against the requirements the order named. A certificate carrying two designations at once has settled nothing and can be read either way afterwards.
- Whose approval the change needsIf the designation came from a project, an end client or your own drawing office, accepting another one is theirs to approve rather than a supplier's. A quotation needs the grade, finish, thickness, width, length and quantity; what was agreed with ZIVO sales before the order is kept on file, and the approval belongs with it.
Q235B Coil From ZIVO
This page stops at the designation. The sizes, the surface conditions, the way the order string is written and the terms a quotation is made on are on the Q235B coil page.
| Product page | Grade | Finish | Thickness | Width |
|---|---|---|---|---|
| Q235B Coil | Q235B | — | — | |
| Pickled and Oiled Coil | Hot rolled pickled and oiled coil | — | — |
Frequently Asked Questions
No. The letter is part of the name, and it selects the acceptance requirements the factory has to meet and report. Writing Q235 leaves that selection open and hands it to whoever makes the steel; writing Q235B makes it. Which letters GB/T 700:2006 defines and what each one requires is in the standard, and this page does not restate them.
Because the standard that carries it is not published free. On 2026-09-20 the Chinese national standards portal listed GB/T 700:2006 as current and offered neither an online preview nor a download, printing instead a notice that the standard adopts standards of international bodies such as ISO and IEC and that copyright prevents an online reading service. Every table in circulation therefore comes from somewhere other than the source of record, and acceptance is settled against the edition named on your order rather than against any page.
They are separate standards rather than two steps of one ladder. GB/T 700:2006 carries the carbon structural grades and GB/T 1591:2018 carries the high strength low alloy structural grades, with their own tables, their own quality classes and their own certificates. The designations are built the same way and look alike on a drawing, which is why they get read as a series. A design that needs the higher-strength route is ordered on the standard written for it.
Not as of 2026-09-20. A revision project registered as 20251168-T-605 would fold it, together with several other documents, into a general-purpose delivery standard, and GB/T 34560.2:2017 already exists alongside it. Neither of those has replaced it: the platform still shows GB/T 700:2006 and GB/T 3274:2017 as current, which is the reason to write the edition on the order instead of leaving it to be looked up later.
More than one, and that is the part most enquiries leave out. The grade and its quality letter come from GB/T 700:2006. The hot rolled flat form is covered by GB/T 3274:2017. The dimensions, shape, weight and permissible deviations come from GB/T 709:2019. Name only the grade and neither the product form nor the tolerance the material will be measured against has been specified.
Sources
- 国家标准 GB/T 700-2006《碳素结构钢》/ Carbon structural steels（标准信息页）
- 国家标准 GB/T 1591-2018《低合金高强度结构钢》/ High strength low alloy structural steels（标准信息页）
- 国家标准 GB/T 3274-2017《碳素结构钢和低合金结构钢热轧钢板和钢带》/ Hot-rolled plates, sheets and strips of carbon structural steels and high strength low alloy structural steels（标准信息页）
- 国家标准 GB/T 709-2019《热轧钢板和钢带的尺寸、外形、重量及允许偏差》/ Dimension, shape, weight and tolerance for hot-rolled steel strip, plate and sheet（标准信息页）
- 国家标准 GB/T 221-2008《钢铁产品牌号表示方法》/ Notations for designation of iron and steel（标准信息页）
- 国家标准检索结果：GB/T 34560.2-2017《结构钢 第2部分：一般用途结构钢交货技术条件》
- 国家标准计划 20251168-T-605《结构钢 第2部分：一般用途结构钢交货技术条件》
- 国家标准条目：GB/T 3274-2017《碳素结构钢和低合金结构钢热轧钢板和钢带》
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