Technical guides
Aluminium specification guides
Reference material on the decisions that get made before an order is placed: which alloy, which temper, which certificate, which finish. Written to be used, not to be ranked.
Index
The guides
5052 vs 6061: Which Aluminium Alloy Do You Actually Need
5052 and 6061 compared on strength, corrosion, weldability, formability and machinability, and the cases where each is wrong.
Aluminium Temper Designations: What O, H and T Actually Mean
How to read temper codes: O annealed, H1x strain hardened, H2x and H3x, T4, T6 and T651. What each does to strength and formability.
EN 10204 Certificates: 2.1, 2.2, 3.1 and 3.2 Explained
What each certificate type confirms: 2.1 declaration, 2.2 test report, 3.1 signed by the mill, 3.2 third-party verified.
Anodising Film Thickness Classes: AA5 to AA25
What anodising classes AA5 to AA25 mean in microns, which class suits interior, architectural and coastal exposure, and how sealing is checked.
ASTM B209 vs EN 485 vs GB/T 3880: Reading Three Standards
How ASTM B209, EN 485 and GB/T 3880 differ on scope, temper notation and tolerance tables, and what to write when a drawing cites another standard.
Coil or Cut-to-Length Sheet: Choosing the Supply Form
When to buy coil and when cut-to-length sheet: decoiler capability, part size, flatness, yield, freight and storage.
Why these exist
Specification is where quality is decided
Most aluminium disputes trace back to an order that never said what acceptable meant. A temper left off a line item, a certificate type left as "MTC", a tolerance left as a nominal number. None of those cost anything to fix on the RFQ, and all of them are expensive to fix afterwards.
These guides are the reference we would want a buyer to have before sending an enquiry. Use them, copy the wording into your own specification, and send it to whoever you buy from — including mills we do not work with.
Also useful
Two tools
The weight calculator works per alloy rather than at a fixed density, which matters at tonnage: 5052 and 7075 differ by about 4%, which is more than a tonne on a 30 tonne order. The grade selector works backwards from what you are making.
Failure modes — pinholes, camber, sensitisation, colour drift and the rest — are covered separately under Aluminium Problems.