SD390 Rebar
SD390: The Number Is Not The Requirement
SD390 belongs to a Japanese designation system, and treating it as a strength label is where procurement enquiries usually go wrong. In the JIS reinforcing-bar framework the SD prefix denotes a steel bar for reinforcement and the number denotes the specified yield point or yield strength — but the designation is only meaningful together with the edition of the standard that defines it and the grade's own ductility and applicability characteristics. So the working questions are not "is it 390?" but: which edition of the standard governs, which of the grades in that edition is actually specified, and what documentation will prove the delivered consignment conforms? SD390 naming is not, by itself, proof of equivalence to an ASTM or BS grade.
Before this grade is ordered
- The edition defines the grade — state it, do not assume it.
- SD390 naming is not proof of equivalence to ASTM or BS grades.
- A specified grade is not permission to use it in every member.
Information current as of
Reading SD390 Before Anything Else
A designation belongs to a standard. Take it out of that standard and it stops meaning anything.
The recurring failure on this grade is treating the number as portable — reading 390 as a strength that can be matched against whatever other standard is in play, and quietly assuming the rest follows. The options below are grouped by what each one actually establishes, so the framework and the edition are settled before the grade is discussed.
SD390 rebar
Current designationChoose it when
When the project governs the Japanese reinforcing-bar standard and specifies the 390 grade, in a bar size and application the project permits and the controlling edition carries.
Before you commit
The designation establishes the grade, not the scope. The edition, the size, the permitted applications and the per-consignment evidence all have to be confirmed separately.
Other grades in the same system
Neighbouring gradesChoose it when
Where the project specifies a different grade from the same family — a legitimate choice that carries its own strength and ductility characteristics.
Before you commit
Grades in this system are not interchangeable by preference. Each has its own characteristics, and a change of grade is a design change the project must confirm.
Rebar sizes
Size referenceChoose it when
Where you need the size and dimensional information alongside the designation, since the grade does not state the bar size.
Before you commit
The designation does not state a size. Confirm the size from the detailing and check it against the controlling edition's dimensional provisions.
Open this referenceRebar mechanical properties
Property referenceChoose it when
Where you need to understand how strength and ductility requirements are framed for a designated grade, and what the documentation must evidence.
Before you commit
The reference is orientation, not acceptance. The controlling edition states the requirement and the consignment documents evidence it.
Open this referenceWhat the designation establishes
The standard framework it belongs to and the grade within that framework's own set — the starting point for the enquiry, not the whole requirement.
What it depends on
The edition of the standard, which is what actually defines which grades exist and what each one specifies. Without it the symbol is unanchored.
What it never establishes
The bar size, the surface form, the applications the project permits, or any equivalence to another standard family's grades.
The scope rule
Transcribe the designation in full, state the controlling edition alongside it, and confirm the bar size and the applications your project permits. Do not treat SD390 naming as proof of equivalence to an ASTM or BS grade — each family defines its own strength characteristics, ductility requirements and test regimes, and none of them transfer on a number match. Where the project governs a different standard family, the reinforcement should be assessed against that family's own designations rather than cross-matched to this one.
JIS Grade Documentary & Application Gate
Anchor the designation, then establish the scope and the proof
This gate refuses to assess the designation on its own. It requires the controlling edition as a field in its own right, holds until the bar size is stated, and will not clear until you have recorded where the project permits the grade. A non-JIS designation entered against this route returns a conflict, because the families are not interchangeable.
Designation & scope inputs
Required fields marked *Use the edition the project specification requires.
Transcribe it exactly as the project specifies it.
The designation states no size — confirm from the detailing.
A specified grade is not permission to use it everywhere — record the project's position.
Required test / document evidence
Nominal mass refers to the base bar and is either supplied by you or confirmed against the controlling standard and the supplied documents. This gate does not estimate weight, does not certify a grade, and does not provide bend diameters or lap lengths.
Scope gate status
Add the controlling edition
The designation is recorded; the edition determines which grades the standard carries, what each one specifies, and the test framework that applies. State the edition the project specification requires.
Documentary items to confirm
- The controlling standard and the edition your project is bound to.
- The exact grade designation as the project specifies it.
- The bar size and surface form the detailing requires.
- The application or member types the project permits this grade in.
- The test and inspection documentation required per consignment.
Boundaries of this gate
- SD390 naming is not proof of equivalence to an ASTM, BS or other grade. Each family defines its own strengths, ductility and test regimes, and none of those requirements travel between them.
- The designation is only meaningful with the edition that defines it — the grades a standard carries and their characteristics can differ between editions.
- SD is a designation prefix, not a strength claim on its own. Read the number as part of the standard's system, not as a standalone value to match across standards.
- The application a grade is permitted in comes from the project and its governing documents, not from the bar mark.
- A general product declaration is not per-consignment evidence. What proves the delivered lot is separate from what the standard requires.
Nothing is transmitted yet, and this gate does not approve a substitution or certify a grade. When the scope and evidence requirements are settled, send the summary to the commercial department for a confirmed quotation.
Standard, Grade & Scope
What the designation says, and everything it leaves to the project
A grade designation identifies a grade inside a standard. It does not carry the edition, the size, the permittable applications or the test evidence with it. The tables below separate those four things, because each is a distinct decision with a different owner.
Designation and scope
Each element of the requirement, and who it belongs to
| Element | What it denotes | What it means for your enquiry | Owner / next action |
|---|---|---|---|
| The SD prefix | A steel bar for reinforcement within this standard's designation system. | Identifies the product family the rest of the symbol belongs to; it is not a strength statement on its own. | State the designation in full. |
| The grade number | The grade within the standard's own set of grades. | Meaningful only against the edition that defines the grade set — not portable to another standard's numbering. | Confirm against the controlling edition. |
| The controlling edition | Not contained in the designation at all. | Defines which grades exist and what each one specifies. It has to come from the project specification. | Engineer states the edition. |
| Bar size & surface form | Not contained in the designation at all. | Physical attributes your detailing sets. Dimensional tolerances and size-related provisions follow from the size. | Designer states size and form. |
| Permitted applications | Not contained in the designation at all. | A specified grade is not permission to use it in every member; the project's governing documents determine scope. | Design authority confirms. |
This table explains how the requirement is composed. Confirm the exact grade set, the grade characteristics and the edition against the current standard documents and your project specification — no numeric performance values are published here.
Across standard families
Why a designation does not transfer between standards
| Designation family | How it is structured | What it means for your assessment | Enquiry field / next action |
|---|---|---|---|
| Japanese industrial standard family (this page) | A designation prefix with a grade number drawn from the standard's own grade set, defined by the edition in force. | The designation belongs to this framework. Its grades and their characteristics are set by the edition, not by the number alone. | State the designation and the controlling edition. |
| ASTM specifications | Grade designations with their own mechanical and chemistry frameworks, defined independently of this system. | Not interchangeable. Similar strength figures do not create equivalence, and detailing or evidence requirements do not transfer. | Confirm the governing standard family. |
| British / European designation systems | Their own designation logic, with strength and ductility expressed according to their conventions. | A comparable-looking number is not a shared designation. The governing standard must be re-stated before any assessment. | State the governing standard and designation. |
This is a non-equivalence reference intended to prevent cross-standard substitution on a number match. It does not establish that any designation is achievable, stocked or permitted for a given project.
Bounded comparison
The adjacent routes worth opening before you commit
Each route answers a specific neighbouring question — the size and dimensional information, and the property framework your documentation has to evidence. Neither is interchangeable with your requirement unless the design authority approves the change.
Rebar sizes & dimensions
Open referenceRebar weight reference
Open referenceMechanical properties
Open referenceThe rebar grade layer
Open referenceComparison is bounded to the stated standard, grade and size basis. Do not substitute a designation, grade or size without an approved design change.
Consignment identity
The designation on the drawing and the bars on site have to meet in the documentation
A designation cannot travel on its own. The requirement on a drawing becomes an enquiry, the enquiry becomes an order, and the order becomes a consignment — and the only thing connecting that consignment back to the original requirement is the marking and documentation delivered with it. That is why the edition matters so much on this grade: if the enquiry is written against one edition and the project is bound to another, the bars may conform to a standard without conforming to your specification, and nothing on site will reveal it until the paperwork is checked. The imagery here illustrates the delivery stage; it is not a representation of a specific consignment.
Test Evidence & Verification
What proves the consignment, and how to check it on receipt
A designation states a requirement. Evidence states what was delivered — and on this page those are held apart deliberately, because the gap between them is where disputes live. Require an identical document set from every source so the offers you compare are comparable.
| Evidence / document | What it verifies | When it is required | Enquiry action |
|---|---|---|---|
| Test / inspection documentation for the consignment | That the material delivered conforms to the requirement, evidenced for that consignment rather than for the product range generally. | Where the project requires certified material — the normal case for a specified grade. | Request at enquiry; confirm it references the delivered consignment. |
| Mechanical results for the delivered lot | The measured performance of the material actually supplied, against the requirement the controlling edition sets. | Where the design relies on the grade's specified characteristics rather than on identification alone. | Request results tied to the consignment. |
| Chemistry information | The composition of the material where the project or the application requires it. | Where the specification, a coating system or a fabrication requirement depends on chemistry. | Request where applicable; not universal. |
| Bar marking & traceability records | The marking that ties a bundle to its documentation and to the requirement on the drawing. | For dimensional checks, schedule control and site traceability. | Confirm marking and traceability requirements. |
| Bundle weight, size & identification tags | Bundle weight, nominal size and the tags naming the consignment. | For schedule control, quantity verification and handling. | Confirm tag content and size identification. |
| Dimensional verification on receipt | That nominal size and form match what was ordered and what the detailing assumed. | On receipt, as part of goods-in inspection. | Agree what is measured and recorded. |
Requirement vs consignment
The standard and the designation state the requirement; the consignment documents state what was delivered. Both are needed, and neither replaces the other.
Issued against the delivery
Documentation is meaningful when it references the consignment actually received, not the product range in general.
Comparable enquiries
Requiring an identical document set from every source is what makes two offers assessable against each other rather than only against a price.
Rebar sizes & dimensions
Check nominal size and dimensional information once the size is confirmed, since the grade designation states no size.
Open technical referenceRebar weight reference
Check unit mass for the bar size once confirmed, for schedule and shipment planning.
Open technical referenceRebar chemical & mechanical properties
See how strength and ductility requirements are framed for a designated grade, and what your documentation must evidence.
Open technical referenceWhere The Grade Does Real Work
The applications where the specified grade is not just a formality
On many jobs the grade designation never comes up again after the drawing is issued, which is exactly why scope assumptions go untested. In the settings below, the grade's characteristics interact with loading, exposure and handling — so an assumed scope is a design change nobody authorised.
Bridge rebar
Why the grade matters here
Bridges combine dynamic loading, exposure and heavy continuity demand, so the grade's ductility characteristics interact with the detailing rather than sitting apart from it.
Fit limit
The bridge's governing specification and exposure class come from the project and are confirmed against it.
Open applicationRebar for road construction
Why the grade matters here
Road and infrastructure work brings repeated loading and joint detailing, where the specified grade is doing structural work rather than being a formality on the drawing.
Fit limit
The pavement or structure type and its governing specification come from the design and are confirmed against it.
Open applicationPrecast concrete rebar
Why the grade matters here
Precast adds controlled casting, form-release timing and lifting stresses, so the specified grade interacts with how the element is handled.
Fit limit
The element type and its lifting design are confirmed against the project; the designation does not override them.
Open applicationApplication fit is confirmed against the controlling standard, the designated grade and the project's own permitted scope when the enquiry is quoted. No generic or unsupported suitability claims are made on this page.
GCC Markets & Destination Planning
Plan the destination, documents and delivery basis for an SD390 enquiry
For each GCC destination the specification, documents and commercial terms are aligned to your project basis at quotation. Because the controlling edition governs what conforms, aligning the enquiry baseline across sources is what makes the offers comparable.
United Arab Emirates
Designation and document review.
Add the delivery location, importer/customs inputs, Incoterm and document set before the SD390 enquiry is issued.
Saudi Arabia
Large project quantities and cross-border documentation.
Confirm the delivery location, importer inputs, Incoterm and documents so a designated-grade requirement is quoted on one consistent basis.
Qatar
Infrastructure technical-approval readiness.
Add the technical submittal and test document package the project requires for the specified grade.
Kuwait
Contractor and fabricator hand-off.
State the delivery location, Incoterm, documents and required date so the order can be planned against the specification basis.
Bahrain
Contractor procurement and industrial supply.
Provide destination, importer/customs inputs, Incoterm and documents before quotation of the SD390 rebar.
Oman
Port-oriented project supply planning.
Confirm the destination, required documents and Incoterm so the quotation basis is fixed for the specified designation.
Destination, documents, port or delivery line, Incoterm and the required delivery date are fixed at quotation from your specification. No served markets, local stock, local branches or delivery times are claimed in advance.
Commercial & Availability Inputs
What turns an SD390 requirement into a comparable offer
Availability, packing, documents, Incoterm and delivery are agreed from your full specification. Price is always on request — no live stock, lead-time or pricing claims are made before quotation.
| Quotation input | What it fixes | Status |
|---|---|---|
| Controlling standard & edition | Which edition the offer is made against — the baseline every source must quote to. | Required before quotation. |
| Grade designation | The grade as the project specifies it, assessed against the edition's own grade set. | Required before quotation. |
| Bar size & surface form | The nominal size and form the detailing requires — the designation states neither. | Required before quotation. |
| Permitted applications | The members and applications the project permits this grade in. | Required before the enquiry is issued. |
| Quantity & unit | Total tonnes or bar count for the schedule. | Required for quotation. |
| Packing & bundle marking | Bundled, strapped and tagged with the designation and consignment identification. | Confirmed from the order. |
| Inspection & documents | The test, inspection and marking records required per consignment. | Fixed at quotation per the standard and service. |
| Availability (stock / mill) | Whether the enquiry is met from current availability or scheduled production. | Confirmed at quotation — never claimed in advance. |
| Incoterm & named place/port | The commercial and delivery basis for the consignment. | Fixed with the destination. |
| Required date | The delivery window the programme depends on. | Confirmed against availability. |
Price, stock, lead time, mill/origin and routing are quotation-dependent unless current verified evidence is present.
Commercial department
The commercial desk checks each SD390 enquiry for the controlling edition, the grade designation, bar size and surface form, the permitted application scope, the required document set and the delivery basis before quoting. Continue to the exporter route when packing, named place, Incoterm, export-document and shipment-planning fields are needed.
Steel rebar exporterOffice 3303, Churchill Executive Tower, Business Bay, Dubai, United Arab Emirates
Monday – Saturday: 8.00 AM – 6.00 PM · Sunday: Closed
Verifiable Outcomes
What each concern is checked against, and what you can rely on
Each risk on this page is mapped to the check that actually addresses it, then to a practical outcome. No superiority claims and no cross-standard equivalence claims are made.
| Buyer concern | Check on this page | Outcome you can rely on |
|---|---|---|
| Matching SD390 to another standard on the strength number | A non-JIS designation entered against this route returns a conflict with the family difference set out. | A cross-standard equivalence assumption is caught at enquiry stage rather than at inspection. |
| Quoting against the wrong edition of the standard | The edition is a required field in its own right, and the gate will not resolve without it. | Every source quotes against the same edition, making the offers comparable. |
| Assuming a specified grade is permitted everywhere | Applicability is collected as its own item, because a grade being specified does not establish where it may be used. | The project's permitted applications are recorded rather than inferred from the bar mark. |
| Losing the bar size between drawing and order | The size is collected separately, because the designation states none. | The order carries the dimensional requirement the detailing assumes. |
| Accepting a general declaration in place of lot evidence | The evidence matrix separates the standard's requirements from the documents proving the delivered consignment. | Conformity is demonstrated on what actually arrived. |
| Comparing offers that are not comparable | The enquiry requires the same edition, grade, size and document set from every source. | Offers can be assessed against each other on specification, not only on price. |
From designation to delivery
- 1
Identify the governing framework
Establish that the project governs the JIS reinforcing-bar standard, and that the SD designation belongs to it rather than being a shorthand for another family's grade.
- Owner:
- Engineer + buyer
- Input:
- Project specification
- Output:
- Governing framework confirmed
- Risk:
- Cross-standard equivalence assumed
Next: Fix the edition
- 2
Fix the controlling edition
State the edition of the standard the project is bound to, since editions differ in the grades they carry and what those grades specify.
- Owner:
- Engineer
- Input:
- Project specification
- Output:
- Edition confirmed
- Risk:
- Edition assumed from the bar mark
Next: Confirm the exact grade
- 3
Confirm the exact grade designation
Record the designation as specified, so it is assessed against the grades the edition carries rather than matched on a number.
- Owner:
- Engineer + buyer
- Input:
- Designation as specified
- Output:
- Grade requirement fixed
- Risk:
- Grade substituted on a number match
Next: Fix size and bar form
- 4
Fix the bar size and surface form
State the nominal size and form the detailing requires, since the designation states neither.
- Owner:
- Designer + detailer
- Input:
- Bar schedule, form
- Output:
- Physical requirements fixed
- Risk:
- Size mismatched at order
Next: Confirm permitted applications
- 5
Confirm permitted applications
Establish the members and applications the project permits this grade in, and apply the detailing provisions that follow.
- Owner:
- Design authority
- Input:
- Permitted use, detailing
- Output:
- Applicability on record
- Risk:
- Grade assumed usable everywhere
Next: Agree the per-consignment documents
- 6
Agree the per-consignment documents
State the test, inspection and marking documentation required against the delivered consignment, identically to every source.
- Owner:
- QA + buyer
- Input:
- Required documents
- Output:
- Evidence requirement fixed
- Risk:
- General declaration substituted for lot evidence
Next: Fix destination and delivery basis
- 7
Fix destination, Incoterm and date
Confirm the delivery location, Incoterm rule and required date so the enquiry is complete and comparable.
- Owner:
- Buyer + commercial
- Input:
- Destination, Incoterm, date
- Output:
- Qualified enquiry ready to issue
- Risk:
- Unstated documents or port
Next: Issue the qualified RFQ
Technical reference note
Which authoritative requirement most changes an SD390 decision
A source-backed note on the requirement this page is built around — stated with its source, its checked date and its limits.
The requirement that changes the decision
The defining feature of this decision is that a grade designation is a reference into a standard, not a self-contained specification. The designation identifies a grade, and the edition of the standard is what defines which grades exist and what each one specifies — its strength characteristics, its ductility behaviour and the tests that verify them. That is why the number in the designation cannot be lifted out and matched against another standard's number: the two numbers are positions within two different systems, and the properties that sit behind them are set independently.
The second consequence concerns scope. A grade being specified for a project does not establish that it is permitted in every member or application — that is a determination the project's governing documents and its design authority make, applied to the specific structure. Separating the designation, the edition, the physical attributes and the permitted scope is what makes an enquiry defensible; conflating them is what produces orders that conform to a standard without conforming to the project.
Primary authority
Japanese Industrial Standards — JIS G 3112, Steel bars for concrete reinforcement — the standard that defines the SD designation system and its grades. Consult the current edition, or your project specification's citation of it, for the grade set and requirements in force.
Designation structure checked · confirm the edition in force and the grade set it carries before specifying
What this note does and does not cover
Covers: how the designation relates to its standard, why the edition defines the grade set, and why a designation does not transfer between standard families.
Does not cover: your project's controlling edition, the grades that edition carries, the design code governing your members, or any equivalence to another standard — each must be taken from the standard and the project directly.
Limit: a standards body's public information is a scope reference, not a substitute for the purchased standard. Nothing here certifies a grade, approves a substitute, or supplies a bend diameter or lap length.
Practical consequence: state the designation and the edition together, confirm the bar size and permitted scope from the project, and require consignment-specific documentation rather than a general conformity claim.
FAQ
What procurement teams ask before an SD390 order is placed
Written for the person who has to make the designation mean the same thing on the drawing, the enquiry and the delivery note.
Is SD390 equivalent to an ASTM or BS grade?
Not by the naming. Each standard family defines its own designations, strength characteristics, ductility requirements and test regimes, and those do not translate into one another automatically. A similar-looking number is not evidence of equivalence. If your project governs a different family, the reinforcement should be assessed against that family's own designations rather than cross-matched.
What does the SD prefix and the number actually denote?
In this system the SD prefix identifies a steel bar for reinforcement, and the number identifies the grade within the standard's own set of grades. The designation is meaningful together with the edition that defines it — the grades a standard carries and what each specifies are properties of that edition, not of the symbol alone.
Why does the edition of the standard matter so much?
Because the edition is what defines the grade set and the requirements attached to each grade. If you quote or order against one edition and the project is bound to another, the grades the standard carries and what they specify may not line up. Stating the edition on the enquiry is what makes offers from different sources genuinely comparable.
What documentation should I require for an SD390 consignment?
Ask for the test or inspection documentation the controlling standard and your project require, tied to the specific consignment delivered rather than to the product range generally, together with bar marking and traceability that connects the material to those records. Require the same document set from every source so the offers can be compared on specification as well as price.
Does specifying a grade mean it can be used anywhere in the structure?
No. A grade being specified in the project does not establish that it is permitted in every member or application. That determination comes from the project's governing documents and its design authority, applied to the specific structure. It is a scope question rather than a property of the bar.
Where does the bar size come from if the designation does not state it?
From your detailing. The grade designation says nothing about nominal size or surface form, so both have to be confirmed from the bar schedule and stated on the enquiry. Size matters beyond ordering accuracy, because dimensional tolerances and size-related detailing provisions follow from it.
Qualified RFQ
Request a quote for SD390 Rebar
Copy the RFQ summary you have built, then send it to the commercial department. The enquiry is ready for review once the controlling edition, the grade designation, the bar size, the permitted applications, quantity, destination and required evidence are complete.
Price, stock, origin and lead time remain quotation-dependent unless current verified evidence is present. This page does not approve a substitution or certify a grade.
Office 3303, Churchill Executive Tower, Business Bay, Dubai, United Arab Emirates
Monday – Saturday: 8.00 AM – 6.00 PM · Sunday: Closed
Copyable RFQ summary
- Standard / edition
- To be confirmed
- Grade designation
- SD390
- Bar size
- To be confirmed
- Permitted applications
- To be confirmed
- Quantity
- To be confirmed
- Destination
- To be confirmed
- Nominal mass (kg/m)
- Confirm per standard / documents
Add any remaining open items — the edition, exact grade, bar size and form, permitted applications, per-consignment documents, availability, price or lead time — as explicit fields before sending.