How to specify 2024-T3 Aluminium on a drawing

2024-T3 Aluminium is an aluminium copper alloy in the T3 temper, known for fatigue resistance. It is used for aerospace sheet and plate parts where the load cycles rather than sits. This entry explains what it is, what the numbers on a data sheet mean, and what to put on a drawing.

It is written from the point of view of the buyer and the drawing office: the values that are realistic in production, the ones that cost money, and the way the result is verified. Where an industry sets the requirement, rail is used as the example: documented welds, coatings and fire smoke toxicity compliance.

What belongs on the drawing

A clear drawing for 2024-T3 Aluminium states the function, the tolerance and the verification, and leaves the route open where the function allows it.

• The feature and its tolerance: ±0.01 mm, applied to the features that locate the part.
• The material and its condition: 2024-T3 aluminium, with the certificate requirement.
• The surface finish: Ra 1.6 µm as machined, called out only where it does something.
• The verification: AS9100 with material traceability, and the standard the report is written to.

Mistakes that cost money

• Machining it bare and leaving it unpainted, which corrodes quickly, which makes the part more expensive without making it better.
• Assuming the fatigue data of 7075 applies here, which makes the part more expensive without making it better.

A workable note

Where a general note is used, say so once in the title block and keep the feature level call outs for the dimensions that matter. Avoid sharp internal corners, which start cracks in a fatigue loaded part

Applications

2024-T3 Aluminium is used for aerospace sheet and plate parts where the load cycles rather than sits, and in practice it appears most often in aircraft skins and ribs, fatigue loaded fittings, racing components, structural brackets.

How it fits into a machining route

The route is fixed before the first part is cut, and it is the route rather than the individual setting that holds the result: material and certificate cost. Where a drawing calls for something the route cannot hold economically, that is raised at quotation rather than after the parts are made.

Standards, documentation and what is issued

The documentation requirement is AS9100 with material traceability. Material is supplied against a certificate where the application calls for it, inspection results are recorded with the job, and the records are kept so that a repeat order can be compared with the first instead of being measured from scratch.

Dimensional inspection with certificate review is the verification step. Where a customer format or a standard report is required, it is agreed before the batch starts, because a report written after the event is a report nobody can use.

Frequently asked questions

What tolerance should be specified for 2024-T3 Aluminium?

±0.01 mm is realistic in production. Tightening it beyond the functional requirement increases cost without improving the part.

Which material is usually used?

2024-T3 aluminium is the usual choice, supplied against AS9100 with material traceability.

How is the result verified?

Dimensional inspection with certificate review, with the results recorded so a repeat order can be compared with the first.

What is the most common mistake?

Assuming the fatigue data of 7075 applies here.

How long does it take and what does it cost?

A realistic cycle is fast cutting with a good chip, and the cost driver is material and certificate cost.

Related capability

If you are specifying 2024-T3 Aluminium on a drawing and want a second opinion on the route, send the model and the quantity. The first response is a manufacturability review with the likely risk points and a quotation, so the decision can be made on facts rather than on a price alone.

Machining, inspection and documentation are handled in one place, which is why the dimensional report and the material certificate arrive with the parts rather than after them.

Related entries

These entries sit next to 2024-T3 Aluminium in the encyclopedia: Ti-6Al-4V Titanium, Inconel 718, Hydraulic Manifolds. Reading them together gives a fuller picture of how the process, the material and the measurement affect each other.