The conversion table we use when a drawing says 5052 and a mill confirmation says 5A02 — and the one field that decides how the sheet behaves.
Chinese designations follow GB/T 3190, not ASTM. 5A02 is the Chinese near-equivalent of 5052, 3A21 of 3003, and 1060 is 1060 in both systems. The letter A marks an aluminium alloy of the older naming series, and the digits after it carry the same meaning as the international four-digit system. A quotation that says only "5052" — or only "5A02" — is incomplete: the temper (H14, H24, H32, H38) is what tells the mill how hard to roll it, and without it two suppliers will ship two different sheets.
If you buy from China and your drawing says 5052, the mill will translate it into its own system before it rolls anything. Knowing that translation is the difference between receiving the sheet you specified and receiving something "similar". This note is the conversion table we use when a customer's drawing and a mill's confirmation have to agree.
The Chinese wrought-aluminium series kept a prefix letter for the alloy family — L for pure aluminium, LF for aluminium-manganese, LY for aluminium-copper, LD for aluminium-silicon — and a newer designation adds 5A02, 3A21, 5A06 and similar codes that map closely onto the international four-digit families. In practice, buyers see the newer codes on mill confirmations and the international codes on their own drawings.
| Chinese designation | Closest international | Typical use on our line | Watch out for |
|---|---|---|---|
| 1060 | 1060 / EN AW-1050A | Light-duty panels, trim | Softer than 3003 at the same thickness |
| 3A21 | 3003 / EN AW-3003 | General sign blanks | Manganese level differs slightly between mills |
| 5A02 | 5052 / EN AW-5052 | Marine, coastal, high-strength blanks | Magnesium range can sit at the low end of 5052 |
| 5A06 | 5083 / EN AW-5083 | Heavy marine and structural | Not a sign-blank alloy; harder to form |
| 6061 | 6061 / EN AW-6061 | Brackets, structural sections | Solution-treated, not a panel alloy |
"Closest" is doing real work in that column. A Chinese 5A02 sheet meets the 5052 composition window in most cases, but if your specification is a certification requirement rather than a material requirement, ask for the certificate and check the chemistry against the ASTM or EN limit.
Alloy says what is in the metal; temper says what has been done to it. The same 5052 can arrive as O (annealed, soft), H32 (strain-hardened and stabilised, quarter-hard) or H38 (fully hard). For a sign blank the difference is visible in your hands: an H32 panel flexes and dents; an H38 panel rings when you tap it and holds flat across a 1200 mm span.
Temper also changes what the sheet will do under the punch. Fully hard tempers crack at a tight bend radius; softer tempers form cleanly but will not stay flat. This is why a drawing that names only the alloy leaves the most consequential decision to the mill's default.
| Temper | What it means | Behaviour on a sign blank |
|---|---|---|
| O | Annealed | Soft, forms easily, will not hold flat |
| H14 / H24 | Strain-hardened, quarter-hard (H24 = hardened and partly annealed) | The 3003 default for inland panels |
| H32 | Strain-hardened and stabilised, quarter-hard | Serviceable but softer than H38 |
| H38 | Strain-hardened, fully hard | The 5052 sign temper: flat, stiff, springy |
Write alloy and temper together on the drawing and on the purchase order — "5052-H38", never "5052". A mill confirmation that returns only an alloy code has not confirmed your order.
Four fields, in this order: alloy and temper, thickness with tolerance, standard the thickness is measured against (EN 485-3 or ASTM B209), and surface condition. Add the certificate requirement if the project has one. Everything else — flatness, burr, hole tolerance — is a fabrication requirement and belongs on the same drawing but in its own block, because it is achieved by a different step.
The failure mode this prevents is common: a drawing says "5052, 2 mm", the mill confirms "5A02 2.0 mm", the sheet arrives at H32 and the sign shop laminates it, and the panel oil-cans on the first hot day. Nobody was dishonest; the specification was incomplete.
Alloy + temper + thickness + tolerance standard + certificate. That is the whole specification of the material; everything else on the drawing describes what to make from it.
Designations for wrought aluminium and aluminium alloys are registered in China under GB/T 3190, "Wrought aluminium and aluminium alloy — Chemical composition", and the international four-digit system is maintained by the Aluminum Association and published in the US as ASTM B221/B209 material specifications from ASTM International. European registrations use the EN AW- prefix under CEN.
Sources: ASTM International, West Conshohocken, PA · CEN, Brussels. Cited 30 October 2026.
Close, not identical. The Chinese designation sits in the same aluminium-magnesium family with a comparable magnesium range, and it is accepted as the practical equivalent in most commercial orders. If the sheet must meet an ASTM or EN limit, verify against the mill certificate rather than the code.
Because 3A21 is the domestic designation for the same aluminium-manganese family. Ask for the chemistry on the certificate if the substitution matters to your specification.
H38 is fully strain-hardened. It gives the stiffness and flatness a sign panel needs across a wide span; the trade-off is limited formability, so tight bends and deep draws are not practical in that temper.
No. Classification follows the product form and alloy family, not the national designation system. Plain sheet is 7606; the invoice description should use the code on the certificate so the customs file is internally consistent.
Specification questions are answered by the same person who quotes the job.