China Q355B Steel Coil Supplier
ZIVO STEEL supplies Q355B as hot rolled uncoated coil. It is ordered on a different GB standard from the carbon structural grades, and that one difference runs through the grade field, the quality class, the tests the mill reports and the certificate you check at the far end.
Q355B
Grades
3 t
Minimum order
Representative view: q355B hot rolled coil, uncoated, the mill scale surface dark and dry.
Q355B Coil From ZIVO STEEL
One sentence pins the scope of this page, because the open web does not. Q355B here is hot rolled uncoated carbon steel coil: no zinc, no aluminium-zinc, no paint. Coated coil built on a Q355B base is a different product with different ordering fields and an extra line on the certificate, and it belongs in the galvanized family rather than in any table here.
ZIVO STEEL is a steel supplier and owns neither a mill nor a rolling line. Q355B coil is arranged with partner factories against what your order specifies, so the order text is the product as far as this page is concerned.
What follows is the Q355B coil route ZIVO supplies under GB/T 1591:2018, with dimensions verified for your order, then the standard family that name sits in, then when a design actually calls for this route, and then the order itself.
Q355B Coil Specifications
One grade on one rolling route, with exact dimensions verified for the order. A dash means that a value is confirmed against the partner offer rather than published in advance.
GB/T 1591:2018 is the edition named for the Q355B grade route. Record the project-approved edition, product form and dimensional standard before comparing a certificate or a quotation. Send the required thickness, width, coil inner diameter and maximum coil mass; ZIVO confirms the complete combination against the actual partner order. No range from another hot-rolled grade is carried into this page.
| Grade | Standard | Process |
|---|---|---|
| Q355B | GB/T 1591:2018 | Hot rolled |
Q355B and the GB Low-Alloy High-Strength Route
Q355B is named in GB/T 1591:2018, the GB standard for high strength low alloy structural steels. That is a different standard from GB/T 700:2006, where the carbon structural grades are named, with its own scope clause, its own tables and its own quality classes. The two families are not two halves of one document, and an order written as though they were will be accepted against a standard nobody checked.
| Layer of the order | What it fixes | Which standard carries it |
|---|---|---|
| The grade standard | The grade name, the quality class letter, and the chemical and mechanical requirements the mill has to meet and report | GB/T 1591:2018, the edition that fully replaced GB/T 1591:2008 |
| The product standard | That what is ordered is hot rolled flat product supplied in coil, rather than a grade with no product behind it | GB/T 3274:2017, the GB product standard for hot rolled plates, sheets and strips in the carbon structural and high strength low alloy families |
| The dimensional standard | Thickness, width, shape, mass and the permissible deviations the coil is measured against | GB/T 709:2019, the GB dimensional standard for hot rolled strip, plate and sheet |
| The surface condition | The state the coil surface is in when it leaves the factory | The order itself: as-rolled with the mill scale on, pickled, or pickled and oiled |
The letter at the end of the designation is the quality class, and it is not decoration. The family runs a ladder of them, and the letter is what selects which set of acceptance requirements the mill has to meet and report, the impact test condition among them. What each class commits the mill to is fixed by the governing edition, and this page does not reprint those tables: the requirement your order is accepted against is read out of the edition itself when the specification is agreed, not out of a supplier's web page.
One piece of history causes more confusion than anything else in this family. The older designation that trade copy still uses for this strength level belongs to GB/T 1591:2008, the edition GB/T 1591:2018 fully replaced, and it is not another way of spelling the current one. If an offer, a stock list or an old drawing comes back with that older name on it, treat it as a question about which edition the order is being written to, and answer the question before the coil is made rather than after the certificate arrives.
When Q355B Is Specified Instead of a Lower-Strength Grade
Moving an order onto this route is not a judgement about which steel is better. It is a decision about which standard the order is accepted against, and it changes the grade field, the quality class, the tests the mill has to report and the table the certificate is compared with. What it does not change is the coil as an object: the rolling route, the surface options and the coil geometry stay exactly where they were.
- What pushes a design up hereA minimum yield the carbon structural family was not selected to deliver, a section that has to carry the same load in less steel, or a code or end specification that names the high strength low alloy standard outright. Any one of the three is a reason on its own.
- The requirement is read at your thicknessA grade designation names a set of requirements, and those requirements are not a single number that holds across every thickness the strip is rolled at. Send the thickness the part is actually made at, and the acceptance values are confirmed against GB/T 1591:2018 at that thickness before the order is placed. This is the detail most often skipped, and the one most often argued about later.
- The quality class still has to be chosenArriving on this route does not settle the class. The letter at the end of the designation selects one, what it commits the mill to is fixed by the edition your order names, and neither the letter nor the edition has a default. Write both, and ask for both on the certificate.
- What stays the sameThe coil is hot rolled, uncoated, and supplied in the same three surface conditions: as-rolled with the mill scale on, pickled, or pickled and oiled. The grade route decides the certificate, not the packing and not the surface.
- When the lower-strength route still answers the drawingIf nothing in the design fixes the higher yield, the carbon structural route is the ordinary one and there is no premium to pay for a class the part will never use. It is written on GB/T 700:2006, with its own quality letter, on its own page.
- Strength is not corrosion protectionMoving up the strength ladder does nothing for the surface. Uncoated coil rusts at whatever rate the storage and the crossing allow it to, whichever grade is written on the tag. If the part needs a coated substrate, that is a different order in a different family.
How to Write a Q355B Order
A quotation needs the grade, finish, thickness, width, length and quantity. On this route the grade field carries two decisions rather than one, because the quality class travels with the designation, and the finish field is a surface condition that has to be picked.
Whatever is agreed with ZIVO sales before the order is written into the specification and kept on file, which is what makes the certificate checkable rather than merely impressive.
- The designation with its quality classQ355B, with the letter, in the grade field and on the purchase order. The letter is what selects the acceptance requirements the mill has to meet and report, so an order that leaves it off has left that choice to the factory.
- The standard code with its editionGB/T 1591:2018 for this route. Code and edition travel together: a designation means what the edition defining it says it means, and a certificate can only be read against an edition somebody named in advance.
- One grade to a lineA quotation that prices two grades on one line has priced neither. They run to different standards, carry different quality letters and come back on different certificates, so each grade gets its own line, its own tonnage and its own price, even when both are wanted on the same shipment.
- The surface conditionAs-rolled with the mill scale on, pickled, or pickled and oiled. One of the three has to be chosen, and it is what decides the condition the coil is in when it reaches your line.
- Thickness, and the thickness the part runs atProvide the design thickness and the applicable tolerance. The values to be checked on a certificate depend on the exact product and standard edition, so the offered thickness must be confirmed for the order instead of inferred from a generic band.
- Width, coil inner diameter and coil weightState the required width, coil inner diameter and maximum coil mass for the receiving line. ZIVO confirms the offered dimensions and weight per order. Identify the applicable GB/T 709 dimensional standard beside any tolerance on the drawing.
- Quantity, and where an order startsOne coil, at least 3 t. Say whether the tonnage is firm or indicative, and whether part deliveries are acceptable, because both change how the material is sourced.
- Uncoated: zinc is a separate orderNothing on this page is coated. If the part needs a zinc coating on this strength level, that is an order in the galvanized family with its own coating field, its own mass and its own line on the certificate.
- What the certificate has to carry backThe standard code with its edition, the designation with its quality class, the heat number, the measured values and the test conditions they were produced under. Ask for the test conditions explicitly: a value without them is a number with no basis.
Have a Specification Ready?
Send what you already know, such as grade, finish, size or quantity. Inquiries are answered within 2 hours.
Inspection and Documents
On this route the certificate has one more job than usual. Besides the standard, the edition and the heat, it has to show the quality class and the conditions the tests were run under, because that is the whole of what the class buys. A row of figures with no test conditions beside it cannot be signed off against a class.
The rest is the ordinary discipline: ask for the mill original, keep the agreed specification where both sides can see it, and decide before shipment rather than after arrival who is going to look at the coil.
- Mill test certificate and packing listBoth travel with every shipment.
- The mill original, not a retypeThe certificate supplied with the shipment is the mill's own, which is the property that makes it worth reading.
- The class, and the test conditions behind itAsk for the standard with its edition, the designation with its quality class, the heat number, the measured values and the conditions those values were produced under, so each line has something on the order to be checked against.
- Before the coil leavesThickness, width, surface, weight, packing and labels are checked by ZIVO before shipment.
- Third-party inspectionSGS, BV or another third party is accepted; the inspection cost is paid by you.
- Label photosPhotos of the coil labels can be provided before the shipment moves.
- The agreed specificationWhat ZIVO sales settled with you before the order is kept on file, and the certificate is read against it rather than against memory.
Packing and Shipment
Loading is normally from Qingdao or Tianjin.
Uncoated coil has no coating to argue about and therefore nothing between the steel and the weather except what the order asked for. The surface condition sets the starting point, and the packing, the edge protection and the rust prevention are settled with ZIVO sales as part of the specification and held on file with it.
A structural grade tends to sit longer than a forming grade, because the fabrication it feeds is scheduled around a building rather than around a press. So say how long the coil will wait, whether it waits under cover, and what the humidity does at your end across a season. Those are specification inputs, and they are only useful while the specification is still open.
Frequently Asked Questions
Order to what the current edition names, and raise the old designation as a question rather than translating it yourself. The older name belongs to a superseded edition of the same GB standard, and an order that carries it is an order whose governing edition nobody has stated. Send the drawing, and the designation, the quality class and the edition are settled with ZIVO sales and written into the specification before anything is made.
Yes, every time. The letter is the part of the designation that selects which acceptance requirements the mill has to meet and report, so an order without it has left that to whoever rolls the coil. Write the class in the grade field, name the edition beside it, GB/T 1591:2018 on this route, and ask for both on the certificate.
Say so in the enquiry and it is agreed as part of the specification before the order, together with the conditions the tests are to be run under. What a quality class requires is set by the governing edition rather than by a supplier's preference, so the useful conversation is about what your acceptance procedure needs to see on the certificate, and it has to happen before the heat is rolled rather than after it lands.
No, and an offer that does it is worth a second look. The two run to different GB standards, carry different quality letters and come back on different certificates, so a single line with one price cannot state which standard either half was accepted against. Ask for one line per grade, each with its own standard, edition, tonnage and price; both can still ship together.
Not from this page. Everything here is hot rolled uncoated coil, and a zinc coating adds a coating type, a coating mass, a measurement basis and a line on the certificate that none of these fields carry. Coated coil is quoted in the galvanized family instead. It is worth saying plainly because search results for this grade mix the two constantly, and an offer that answers an uncoated enquiry with a coated product is answering a different question.
One coil and at least 3 t. Prices are quoted in US dollars, FOB Qingdao, payment is 30% T/T deposit and 70% balance before shipment, and the lead time is fixed once the specification and the quantity are.
Tell Us What You Need
Send the product form, grade, finish, thickness, width, length and quantity. Inquiries are answered within 2 hours.
Send Your Inquiry
Name, email and your inquiry are all that is needed. Add a WhatsApp number if you prefer to chat.
- Email: henry@zivosteel.com
- WhatsApp: +86 15668396618
- Address: 2F, Vanke Center, Lixia District, Jinan, Shandong, China
- Hours: Monday to Saturday, 8:00-18:00 (China time)