T351
Solution treated, stretched 1.5 – 3 %, naturally aged. The standard temper for machining block: high toughness and fatigue strength, stable in machining.
Fatigue-resistant machining block
2024 Aluminium Block
2024 aluminium block is cut from thick 2024-T351 plate or forged block and machined into parts that must carry high, repeated loads: aircraft fittings, actuator housings, racing components and high-strength fixtures. It combines about 470 MPa typical tensile strength with excellent fatigue resistance and good machinability. Metline supplies 2024 block cut to size in T351 and other tempers, certified to ASTM, AMS and EN, worldwide.
- Alloy
- 2024 (Al-Cu-Mg)
- Tempers
- T351, T851, O
- Thickness
- Approx. 25 – 150 mm plate; larger forged
- Standards
- ASTM B209 · AMS 4037 · EN 485
What is 2024 aluminium block?
"Block" is a buyer’s term rather than a separate product standard. In practice, 2024 block is either thick rolled plate (to ASTM B209 or AMS specifications) saw-cut into rectangular pieces, or an open-die forged block for sizes beyond the plate range. Either way, the material is 2024: the original high-strength aluminium-copper-magnesium aircraft alloy.
2024 is chosen when fatigue strength and damage tolerance matter more than peak static strength. It is weaker than 7075 but resists crack growth better, which is why it remains standard for tension-loaded aircraft structure and many machined fittings. In the T351 temper the plate is solution treated, stretched to relieve quench stress and naturally aged, so blocks stay stable when large amounts of material are removed.
Its weak points are corrosion resistance and weldability. The high copper content makes bare 2024 susceptible to pitting and intergranular attack, so finished parts are normally anodised, conversion coated and painted. Arc welding is not recommended.
2024 chemical composition (wt %)
| Element | Minimum | Maximum | Role |
|---|---|---|---|
| Copper (Cu) | 3.8 | 4.9 | Main strengthening element (Al2CuMg precipitates) |
| Magnesium (Mg) | 1.2 | 1.8 | Accelerates natural ageing and raises strength |
| Manganese (Mn) | 0.30 | 0.9 | Grain control, toughness |
| Silicon (Si) | — | 0.50 | Impurity |
| Iron (Fe) | — | 0.50 | Impurity |
| Chromium (Cr) | — | 0.10 | |
| Zinc (Zn) | — | 0.25 | |
| Titanium (Ti) | — | 0.15 | Grain refiner |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder | About 90.7 – 94.7 % |
Registered Aluminum Association limits; EN AW-2024 under EN 573-3 is the same alloy.
Mechanical and physical properties
Typical values describe thin and moderate sections. In thick plate, specified minimums fall as thickness increases because the centre cools more slowly during quenching; the ASTM B209 and AMS tables give the limits by thickness band, and the certificate shows the tested values.
| Temper | Tensile strength | Yield strength (0.2 %) | Elongation | Hardness |
|---|---|---|---|---|
| O (annealed) | 186 MPa / 27 ksi | 76 MPa / 11 ksi | 20 % | 47 HB |
| T351, typical | 470 MPa / 68 ksi | 325 MPa / 47 ksi | ≈ 19 % | 120 HB |
| T851, typical | ≈ 480 MPa / 70 ksi | ≈ 450 MPa / 65 ksi | ≈ 6 % | ≈ 128 HB |
Typical physical properties (T351)
- Density
- 2.78 g/cm³ (0.100 lb/in³)
- Modulus of elasticity
- 73.1 GPa (10,600 ksi)
- Fatigue strength (5×10⁸ cycles)
- 138 MPa (20 ksi)
- Shear strength
- 283 MPa (41 ksi)
- Thermal conductivity
- 121 W/m·K
- Electrical conductivity
- ≈ 30 % IACS
- Melting range
- 502 – 638 °C
Which temper for 2024 block?
T851
T351 material artificially aged. Higher yield strength and better resistance to intergranular and stress corrosion, with lower elongation and toughness. Useful for parts in warm service.
T352 / forged
Forged blocks are stress-relieved by compression (T352) rather than stretching, for sizes beyond the plate range.
O
Annealed. Bought only when the part will be formed or heat-treated after machining.
Standards and equivalents
| System | Designation / specification |
|---|---|
| ASTM | ASTM B209 (sheet and plate); ASTM B247 (forgings) |
| SAE AMS | AMS 4037 (T3 / T351 sheet and plate); AMS-QQ-A-250/4 |
| UNS | A92024 |
| European (EN) | EN AW-2024 / AlCu4Mg1; EN 485-2 plate; Werkstoff 3.1355 |
| Japan (JIS) | A2024 (JIS H4000) |
| China (GB) | 2024; 2A12 is the closest traditional Chinese grade |
2024 block sizes and weights
Supply range
- Plate-cut block thickness
- Approx. 25 – 150 mm (1 – 6 in); thicker on enquiry
- Width and length
- Cut to size from plate up to about 1250 – 1500 mm wide
- Forged block
- Larger cross-sections to drawing
- Cutting
- Band-saw or circular-saw cut; milled faces on request
- Protection
- Oiled or wrapped; cut edges marked with alloy, temper and lot
2024 weighs 2.78 kg per litre (2.78 g/cm³), so a block weight in kg is thickness × width × length in mm × 2.78 ÷ 1,000,000.
| Block size (mm) | Weight (kg) |
|---|---|
| 50 × 100 × 200 | 2.78 |
| 50 × 300 × 300 | 12.51 |
| 75 × 200 × 400 | 16.68 |
| 100 × 200 × 300 | 16.68 |
| 100 × 300 × 500 | 41.70 |
| 150 × 300 × 600 | 75.06 |
| 200 × 400 × 600 | 133.44 |
| 250 × 500 × 1000 | 347.50 |
| 300 × 600 × 1200 | 600.48 |
Tolerances and inspection for 2024 block
- Saw-cut blocks are typically supplied with a small positive allowance (for example +1 to +3 mm) so all faces can be cleaned up; tighter milled tolerances on request
- Thickness tolerance of the parent plate per ASTM B209 / ANSI H35.2 or EN 485-3
- Ultrasonic inspection to AMS-STD-2154 classes for aerospace orders, on request
- Electrical conductivity and hardness checks as temper verification
- EN 10204 3.1 mill certificate with chemistry and mechanical test results, traceable to the parent plate lot
Machining, joining and protecting 2024
Machining
Machines very well in T351: chips break cleanly and surfaces are bright. Use sharp carbide, high speeds and coolant. Balance material removal from both sides of thick blocks to limit distortion.
Joining
Not suited to arc welding. Assemble with rivets or bolts; friction stir welding is used in some aerospace structures.
Corrosion protection
Anodise (sulphuric or chromic), apply conversion coating and prime. Isolate from carbon fibre and stainless steel to avoid galvanic attack.
Temperature
Keeps strength better than 7075 up to about 120 – 150 °C; T851 is preferred for sustained warm service.
Where 2024 block is used
- Aerospace: wing and fuselage fittings, brackets, hinges and actuator parts
- Defence: missile and weapon components needing fatigue strength
- Motorsport: uprights, suspension mounts and brake components
- Tooling: high-strength fixtures and gauges
- Industrial: hydraulic manifolds, gear housings and screw-machine parts
2024 block compared with 7075 and 6061 block
| Property | 2024-T351 | 7075-T651 | 6061-T651 |
|---|---|---|---|
| Typical tensile strength | 470 MPa | 572 MPa | 310 MPa |
| Typical yield strength | 325 MPa | 503 MPa | 276 MPa |
| Fatigue / crack growth | Best of the three | Good | Fair |
| Corrosion resistance | Fair | Fair | Very good |
| Weldability | Poor | Poor | Good |
| Relative cost | High | High | Low |
Pick 2024 for fatigue-driven parts, 7075 for maximum static strength and stiffness of small parts, and 6061 for general machined components where cost, corrosion and weldability matter more. See the 2024 vs 7075 comparison for a deeper look.
How to order 2024 block
- SpecifyAlloy and temper, block dimensions with machining allowance, quantity, and the governing standard (ASTM B209, AMS 4037 or EN 485). Attach a drawing if the material will be cut or machined to shape.
- QuoteWe confirm availability, tolerances, certification and delivery terms (EXW, FOB, CIF or DAP) for your destination.
- ProcessMaterial is cut to length or size on request, marked for traceability and inspected for dimensions and surface.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing chemistry and mechanical results; third-party inspection can be arranged.
- ShipExport packing in seaworthy wooden cases or on pallets with moisture protection, by sea or air to your port or door.
References and standards
- ASTM B209 – Aluminum and Aluminum-Alloy Sheet and Plate
- SAE AMS 4037 – Aluminum Alloy Sheet and Plate, 2024-T3 / T351
- EN 485-2 – Sheet, strip and plate: mechanical properties
- AMS-STD-2154 – Inspection, Ultrasonic, Wrought Metals
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
2024 aluminium (aluminum) block: frequently asked questions
What is the difference between 2024 block and 2024 plate?
Usually none in material terms: block is thick plate cut into rectangular pieces. For sizes beyond the plate range, forged block is used and is stress-relieved by compression (T352) instead of stretching.
How strong is 2024-T351 block?
Typical values are about 470 MPa tensile and 325 MPa yield. Specified minimums fall with thickness, so check the band that matches your block on the certificate.
Is 2024 better than 7075 for machined parts?
7075 is stronger and harder, but 2024 has better fatigue and crack-growth resistance. Choose by the load case: static strength favours 7075, cyclic tension favours 2024.
Does 2024 block need corrosion protection?
Yes. Bare 2024 is prone to pitting and intergranular corrosion. Anodise or conversion coat and paint finished parts.
How do I calculate the weight of a 2024 block?
Multiply thickness × width × length in mm by 2.78 and divide by 1,000,000 to get kg. A 100 × 200 × 300 mm block weighs about 16.7 kg.
Can you cut blocks to my drawing?
Yes. Blocks are saw-cut to size with a clean-up allowance, or milled to tighter tolerances on request, and shipped worldwide.
Need 2024 block cut to size?
Send the block sizes, temper, quantity and specification. We will reply with availability and a delivered price.
