What is the difference between 6063 and 6061 for 2020

For a 2020 (and the rest of the catalogue T-slot family) the practical difference is that 6063-T5 is the extrusion- and finish-first choice, while 6061-T6 is a strength- and machining-first upgrade that costs more to run and may need thicker walls on the same envelope.

On a 20 × 20 mm multi-slot section, 6063 fills the lips and core hole more reliably at production speed. 6061’s copper-bearing chemistry raises strength but slows the press and can mark anodising. Buyers who ask for “6061 2020” often want higher proof stress on a fixture rail; confirm whether the real need is yield, hard-coat anodising, or CNC faces — many of those jobs are better as 6063-T5 with a larger series (3030/4040) because I, not alloy, sets deflection.

Minima vary with thickness and standard; treat the table as selection guidance and lock values to the mill certificate.

What alloy and temper is a 2020 profile normally supplied in

A catalogue 2020 T-slot is normally supplied in 6063-T5 unless the purchase order explicitly states another alloy-temper pair.

That default holds across 3030, 4040 and most library industrial dies: 6063-T5 balances slot tolerance, surface for clear or colour anodising, and cost. 6063-T6 is available when you need more strength without leaving the 6063 chemistry. 6061-T6 or 6082-T6 are made-to-order on many T-slot tools and may raise MOQ behaviour toward the new-die / special-release path even when the cavity already exists. Finish callouts (mill, anodised per EN ISO 7599, powder) sit beside the temper, not instead of it.

Can the supplier substitute the alloy grade without telling me

No — alloy and temper on the purchase order are part of the product definition; a silent swap from 6063-T5 to another 6xxx or from T5 to T6 is a nonconformance unless the contract allows an approved alternate.

Substitution changes certified mechanicals, anodising response and sometimes weld procedure qualification. Importers and OEM buyers should state alloy-temper on the drawing and the PO, require a mill certificate with the lot, and reject unmarked bars. If billet availability forces a change, the supplier must propose the alternate in writing before metal runs, with updated mechanical minima and any effect on price or lead time. Die making still adds 7–12 days when a new cavity is needed; alloy change on an existing die is a process change, not a free substitution.

Commercial frame for 2026 releases remains MOQ 150 m on an existing die and 500 m on a new die, T/T 30% deposit + 70% before shipment or L/C at sight, shipped FOB, CIF, DAP or DDP from Shanghai or Ningbo unless agreed otherwise.

What actually differs

What actually differs among 6063, 6061 and 6082 — and between T5 and T6 — is strength, extrudability and surface response; what does not differ enough to matter for most frames is elastic modulus.

6063’s leaner chemistry flows through complex T-slot dies and takes anodising evenly, which is why catalogue framing stays there. 6061 and 6082 trade that flow for higher proof stress and better machining chips, which matters on CNC plates, heavily tapped ends and structural members sized by stress rather than by deflection. T5 is the economical press-cool-and-age route used on most 6063 framing; T6 is the higher-strength heat-treat route buyers name when the print shows elevated minima. Pick alloy for chemistry-sensitive properties (finish, weld, certified yield). Pick section size for stiffness. Mixing those two decisions is how projects order 6061 2020 and still watch the rail sag.