“EN 10346 SA1D aluminized steel tube” is a cross-standard wording that should be corrected before it reaches a purchase order. SA1C, SA1D, SA1E and SA1F belong to the JIS G 3314 system for hot-dip aluminium-coated steel sheet and strip, while EN 10346 uses designations such as DX51D, DX52D, DX53D, DX54D and DX56D together with coating symbols such as +AS. 

1. Why “EN 10346 SA1D” Appears in Searches

The mixed expression usually comes from a drawing, supplier quotation, old technical file or translated specification that combines two standards in one product description. A European buyer may search for “EN 10346 SA1D aluminized steel tube” because the tube is intended for a European project while the original material reference was written under JIS G 3314.

There are several common reasons:

• A Japanese material designation was copied into a European project specification.
• A supplier converted JIS grades into an EN equivalent but retained the original SA1D wording.
• A translated drawing combined the coating designation from one standard with the substrate grade from another.
• The buyer wants dual-standard documentation for a multinational project.

The solution is not to delete one standard blindly. Instead, identify which standard controls the steel grade, which controls the coating, and which specification controls the finished tube.

2. SA1D Belongs to JIS G 3314

JIS G 3314 covers hot-dip aluminium-coated steel sheet and strip. The JIS family includes SA1C, SA1D, SA1E and SA1F, representing progressively more demanding forming categories. A current Japanese steel producer's JIS G 3314 summary identifies SA1C as commercial quality, SA1D as drawing quality, SA1E as deep-drawing quality and SA1F as ultra-deep-drawing quality. 

JIS G 3314 also uses aluminium coating designations such as 40, 60, 80, 100 and 120. Therefore, a designation such as SA1D 120 combines a JIS forming grade with an aluminium coating designation.

3. EN 10346 Uses DX Grades Instead

EN 10346:2015 identifies cold-forming steel grades such as DX51D, DX52D, DX53D, DX54D, DX55D, DX56D and DX57D. For these grades, +AS identifies an aluminium-silicon coating. The standard's table explicitly lists DX51D through several higher-formability grades with +AS as an available coating type. 

Thus, SA1D should not be inserted into an EN 10346 material designation. The European designation should remain in the DX family, with +AS identifying the aluminium-silicon coating.

4. The Important Cross-Reference: SA1D vs DX53D+AS

This is where many online descriptions become misleading. A commonly published industry cross-reference maps JIS SA1D to EN DX53D+AS, while SA1C maps to DX51D+AS. Other commercial tables may show slightly different mappings depending on the edition, mechanical-property window and whether the comparison is based on forming class, chemical composition or guaranteed mechanical properties. 

5. Why DX51D+AS120 and SA1D 120 Should Not Be Called Identical

The coating can be similar while the substrate classification is different. DX51D is the commercial-quality end of the EN cold-forming family, whereas SA1D is a JIS drawing-quality designation. Treating them as identical can create an unintended change in forming performance.

The same issue applies to coating mass. A designation such as AS120 is commonly used for a total aluminium coating mass of approximately 120 g/m² on both sides in commercial EN product data, while JIS G 3314 also provides a 120 coating designation. Nevertheless, the buyer should confirm the exact test method and guaranteed minimum because the standards define their own measurement rules. For EN 10346, commercial product data lists AS120 at a 120 g/m² minimum two-sided coating mass under the specified sampling method. 

6. Why This Matters for Tube Production

When pre-coated strip is converted into tube, the substrate grade affects forming behaviour, while the AS coating provides the intended aluminium-silicon surface system. A mismatch can therefore appear during roll forming, bending or tube fabrication even when the coating designation looks correct.

For example, if the drawing requires a drawing-quality aluminized strip but the supplier substitutes a commercial-quality substrate simply because both carry an AS120 coating, the coating requirement may be met while the forming requirement is not.

7. If the Customer Requires Both JIS and EN

A dual-standard order can be supplied, but it should be written as a dual-compliance requirement, not by merging the two designations into one fictional grade.

The supplier should state clearly whether the material actually complies with both standards or whether one designation is provided only as an equivalent reference. “Equivalent” and “dual certified” are not the same statement.

8. Recommended Purchase Order Wording

The final wording should be confirmed against the project's governing specification. Cross-reference tables are useful for sourcing, but they should not replace a formal comparison of guaranteed properties when certification is contractually required.

9. Teda Ganghua Commercial Supply Support

For European projects involving aluminized tubes, Teda Ganghua can help separate the substrate grade, aluminium-silicon coating, coating mass and finished tube specification before quotation. This is particularly useful when a customer's drawing contains JIS terminology while the project specification requests EN documentation.

For sourcing support, see aluminized steel and provide the original drawing designation, required standard, grade, coating mass, tube dimensions, quantity and inspection-document requirements. The supply specification can then be checked before production rather than after the material reaches inspection.

10. FAQ

Is SA1D an EN 10346 steel grade?

No. SA1D belongs to JIS G 3314. EN 10346 uses DX-series grades such as DX51D, DX52D, DX53D and DX54D for cold-forming applications. 

What is the common EN equivalent of JIS SA1D?

A commonly used cross-reference places JIS SA1D against EN DX53D+AS for aluminium-silicon-coated material. The exact equivalence should still be verified against the required mechanical properties, coating mass and applicable standard edition. 

Is DX51D+AS120 equivalent to SA1D 120?

Not as a direct grade equivalence. DX51D is generally associated with the commercial-quality level, while SA1D is a drawing-quality JIS designation. A more appropriate comparison is commonly SA1C ↔ DX51D+AS and SA1D ↔ DX53D+AS, subject to specification verification.

Does AS120 mean the same thing in EN and JIS?

The number 120 is used for an aluminium coating designation in both commercial EN and JIS product descriptions, but the exact guaranteed value and measurement method must be confirmed from the governing standard and purchase specification. JIS G 3314 documentation lists 120 as an available aluminium coating designation, while EN product data lists AS120 as a 120 g/m² two-sided coating class. 

Can a customer request both EN 10346 and JIS G 3314?

Yes, but the order should explicitly state whether the material must fully comply with both standards or whether one is being supplied as an equivalent reference. For dual certification, the supplier should verify the chemical, mechanical, coating and dimensional requirements of both standards rather than simply printing two names on the MTC.