JIS G3314 SA1D is a drawing-quality grade for hot-dip aluminium-coated steel sheet and strip, positioned above commercial-quality SA1C when forming requirements become more demanding. The important procurement point is that JIS G3314 covers coated sheet and strip rather than finished tubes. Therefore, an aluminized steel tube made from SA1D material should specify the JIS feedstock grade together with the tube dimensions, forming process, welding requirements, and any additional tube standard. The current JIS G3314 edition is 2022 and specifies requirements for hot-dip aluminium-coated steel sheet and strip. 

1. SA1D: Drawing Grade Within JIS G3314

SA1D belongs to the drawing-quality side of the JIS G3314 grade family. In practical sourcing, it is selected when the blank must undergo more controlled forming than a general commercial-quality SA1C sheet. The distinction matters when the final tube begins as a formed shell, curved section, deep-drawn component, or other geometry where cracking and local thinning must be controlled.

JIS G3314:2022 covers hot-dip aluminium-coated steel sheet and strip and includes separate provisions for coating, mechanical properties, bendability, tensile properties, dimensions, appearance, inspection, marking, and reporting.

2. SA1D vs SA1C: Why Forming Capability Matters

SA1C is normally selected for commercial-quality applications where forming requirements are relatively moderate. SA1D is intended for drawing applications, so procurement teams should focus more closely on mechanical properties, elongation, bendability, blank shape, forming depth, and the possibility of localized deformation.

The practical difference is therefore not simply a label change. A buyer selecting SA1D should communicate the actual forming geometry and deformation level so that the material is evaluated for the intended manufacturing route.

3. What Tests Should Be Checked?

JIS G3314:2022 separates mechanical properties into bendability and tensile-related requirements, while its test section also covers chemical analysis, coating tests and mechanical tests. The standard's structure specifically identifies bendability, yield point or proof stress, tensile strength and elongation as mechanical-property items.

Important purchasing clarification: “cup test” is often used by buyers and manufacturers as a practical forming evaluation, but it should not automatically be described as a mandatory universal JIS G3314 test. For a demanding deep-drawing project, specify the required cup or forming test method, specimen condition and acceptance criteria in the purchase specification.

4. Bend Test: Coating and Base Steel Both Matter

Bending evaluates more than the steel substrate. The aluminium coating must remain sufficiently adherent when the sheet is deformed. This is particularly important when SA1D feedstock is subsequently rolled, pressed, bent or formed into a tube section.

For production approval, the buyer should define the required bend condition according to thickness, forming direction, tooling and the final component geometry. A successful material test does not automatically guarantee successful forming under every production radius because actual tooling, lubrication, blank design and deformation history also influence the result.

5. Cup Testing for Deep-Draw Applications

A cup or deep-drawing evaluation can provide more application-specific information than a simple tensile test. A cylindrical cup test, for example, can reveal how the sheet flows under biaxial deformation and whether the blank is likely to fracture at a critical forming location. Deep-drawing research commonly evaluates drawability through cylindrical cup tests and limiting draw ratios. 

For an SA1D tube project, this type of evaluation can be useful when the production route involves deep drawing before welding, or when a formed housing is later converted into a tubular or enclosed component. The buyer should provide the actual forming depth, blank dimensions, punch geometry and acceptance criteria when requesting a dedicated forming trial.

6. Typical Deep-Forming Applications

The exact end use should determine whether SA1D is sufficient or whether a more specialized drawing specification and additional forming validation are necessary.

7. Coating Specification Must Be Separated From Grade

SA1D identifies the base material quality level, while the coating designation identifies the aluminium coating requirement. These should not be treated as the same specification. JIS G3314 separately addresses coating composition, coating mass and coating adherence. 

For tube procurement, also distinguish the coating requirement on the outside from any requirement for the inside surface. If the final tube must have internal aluminium protection, the buyer should state this explicitly rather than assuming that a coated sheet automatically produces the required internal coating condition after forming and welding.

8. Supply and Lead-Time Considerations

For project purchasing, SA1D availability should be checked together with thickness, width, coating mass, coil or sheet form and the required processing route. Drawing-grade coated material can require more careful production scheduling than standard commercial stock because the supplier must match the requested grade, coating and forming performance.

For production planning, a supplier should confirm whether the requested specification is available from stock or requires production, then provide a realistic manufacturing and inspection schedule rather than quoting a generic delivery period.

9. How to Write the Purchase Order

A clear order should not simply say “SA1D aluminized tube.” Because JIS G3314 is a sheet-and-strip standard, the purchasing description should distinguish the material feedstock from the finished tube requirements.

For a formed tube, the final specification may therefore be written in two layers: JIS G3314 SA1D coated steel feedstock followed by the applicable finished-tube manufacturing and dimensional requirements. This avoids treating a sheet grade as if it were itself a complete tube standard.

10. SA1D Supply for Forming-Focused Projects

For buyers comparing suppliers, the most useful qualification questions are whether the supplier can provide the requested JIS grade, whether the coating mass is documented, whether mechanical and coating tests are traceable, and whether the material can be supplied in the dimensions required for the forming process.

Teda Ganghua can support procurement of SA1D aluminized steel with material specification review, dimensional confirmation, inspection documentation and customized processing coordination. For tube projects, provide the required OD, wall thickness, length, coating requirement and forming route so the supply specification can be checked before production.

11. FAQ

Is SA1D a finished tube standard?

No. JIS G3314 specifies hot-dip aluminium-coated steel sheet and strip. A tube made from SA1D material needs additional finished-tube dimensional and manufacturing requirements.

Is SA1D more suitable for forming than SA1C?

Yes. SA1D is positioned as a drawing-quality grade, while SA1C is commercial quality. The final choice should still be based on the actual forming geometry and required mechanical properties.

Does JIS G3314 require a cup test for every SA1D order?

Do not assume so. The standard explicitly covers mechanical tests including bendability and tensile-related properties; a cup or deep-drawing evaluation should be specified separately when required by the application. 

What should be included when buying SA1D tube?

Specify the JIS G3314 SA1D feedstock, coating designation, dimensions, tube OD and wall thickness, length, forming and welding requirements, internal/external coating requirements, and inspection documentation.

Which JIS G3314 edition should be referenced?

JIS G3314:2022 is the current revised edition identified in the published standard and replaced the 2019 edition. Contract documents should state the exact edition required by the project.