Closed-die forgings
Near-net-shape fittings, frames and housings for repeat production.
Aerospace · die and hand forgings
7075 Aerospace Aluminium Forgings
7075 forgings give high strength with grain flow that follows the shape of the part, which improves fatigue life in fittings, frames and landing-gear parts. They are supplied in T6 for maximum strength or in the overaged T73 and T7352 tempers when resistance to stress-corrosion cracking is required. Metline supplies 7075 die forgings, hand forgings, rings and forged blocks with full certification to customers worldwide.
- Alloy
- 7075 (Al-Zn-Mg-Cu-Cr)
- Tempers
- T6, T652, T73, T7352
- Forms
- Die, hand and ring forgings
- Standards
- AMS 4126 · 4141 · 4147 · ASTM B247
Where 7075 forgings fit
Forging refines the cast structure and aligns the grain along the contours of the part. For a lug, a fitting or a gear housing, that grain flow gives better fatigue life and short-transverse properties than the same part machined from plate or bar.
7075 has been forged for aircraft parts for decades. In T6 it reaches the highest strength, but thick T6 forgings are prone to stress-corrosion cracking, which led to the development of the T73 temper. 7075-T73 and T7352 forgings have excellent stress-corrosion resistance at somewhat lower strength and remain widely specified for fittings and gear parts. For thick sections that need both high strength and corrosion resistance, 7050-T74 and 7175-T74 forgings are the usual upgrades.
7075 chemical composition (wt %)
| Element | Minimum | Maximum | Role in the alloy |
|---|---|---|---|
| Silicon (Si) | — | 0.40 | Impurity |
| Iron (Fe) | — | 0.50 | Impurity |
| Copper (Cu) | 1.2 | 2.0 | Adds strength; improves stress-corrosion resistance in T73 |
| Manganese (Mn) | — | 0.30 | Residual |
| Magnesium (Mg) | 2.1 | 2.9 | Forms MgZn2 with zinc |
| Chromium (Cr) | 0.18 | 0.28 | Grain control; resists recrystallisation and stress corrosion |
| Zinc (Zn) | 5.1 | 6.1 | Main strengthening element |
| Titanium (Ti) | — | 0.20 | Grain refiner |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder | About 87.1 – 91.4 % |
7075 forging tempers and typical properties
Values are approximate typical figures for moderate sections. Specifications set separate minimums by thickness and test direction, and short-transverse values are lower.
| Temper (specification) | Tensile strength (typical) | Yield strength (typical) | Description |
|---|---|---|---|
| T6 (AMS 4126) | About 550 – 570 MPa | About 480 – 500 MPa | Peak aged; highest strength, lowest stress-corrosion resistance |
| T652 | About 550 MPa | About 480 MPa | As T6, compressed after quenching to relieve stress |
| T73 die forgings (AMS 4141) | About 470 – 500 MPa | About 400 – 430 MPa | Overaged; excellent stress-corrosion resistance |
| T7352 (AMS 4147) | About 470 – 500 MPa | About 390 – 420 MPa | Overaged and compressed; low residual stress for heavy machining |
T352 and T74 are not standard 7075 forging tempers; T352 belongs to 2xxx alloys, and T74 forgings are normally made in 7050 or 7175. Some published tables give T73 forgings the same minimum strength as T6, which is incorrect.
Physical properties
- Density
- 2.81 g/cm³ (0.101 lb/in³)
- Modulus of elasticity (tension)
- About 71.7 GPa (10,400 ksi)
- Shear strength (T6)
- About 330 MPa (48 ksi)
- Fatigue strength (T6, 5×10⁸ cycles, R.R. Moore)
- About 160 MPa (23 ksi)
- Thermal conductivity
- About 130 W/m·K (T6); about 155 W/m·K (T73)
- Electrical conductivity
- About 33 % IACS (T6); about 40 % IACS (T73)
- Coefficient of thermal expansion
- About 23.4 µm/m·°C (20 – 100 °C)
- Melting range
- About 477 – 635 °C
7075 forging specifications
| Specification | Scope |
|---|---|
| AMS 4126 | 7075-T6 forgings |
| AMS 4141 | 7075-T73 die forgings up to 6 in thick, and forging stock |
| AMS 4147 | 7075-T7352 forgings |
| AMS-QQ-A-367 | Aluminium alloy forgings, several alloys including 7075 |
| ASTM B247 | Die forgings, hand forgings and rolled ring forgings |
| AMS-STD-2154 | Ultrasonic inspection |
| UNS / EN | A97075 / EN AW-7075, EN 586 |
Forging types
Hand forgings and blocks
Open-die blocks, bars and simple shapes for prototypes and large machined parts.
Rolled rings
Seamless rings for mounts, flanges and rotating structures.
Discs and shafts
Upset discs and stepped shafts for hubs and actuator parts.
Size and weight limits depend on the press and heat-treatment route chosen for each part; send the machined-part envelope and we will propose the forging type and stock.
Machining, inspection and finishing
7075 forgings machine very well in all tempers. T652 and T7352 forgings hold shape best during heavy material removal. Typical inspection includes tensile and hardness tests, conductivity checks on T73 tempers, ultrasonic inspection and, for new die forgings, grain-flow macro-etch and first-article inspection. Fusion welding is not recommended; finished parts are anodised or conversion coated and primed, and fatigue-critical areas are often shot peened.
Typical uses of 7075 forgings
- Airframe fittings: wing and fuselage attachment fittings, hinge brackets and lugs
- Landing gear: links, braces and wheel parts on lighter aircraft
- Helicopters: rotor and transmission fittings
- Missiles and defence: structural forgings, fins and housings
- Industrial: high-strength gears, shafts, valve parts and keys
How to order 7075 forgings
- SpecifyAlloy and temper, drawing or envelope dimensions, quantity and the governing specification with its revision (AMS 4126, AMS 4141, AMS 4147, AMS-QQ-A-367 or ASTM B247).
- ConfirmWe confirm the specification can be met, the tolerance class, any extra tests (ultrasonic class, conductivity, fracture toughness) and the delivery terms (EXW, FOB, CIF or DAP).
- InspectMaterial is checked for dimensions, straightness or flatness and surface condition; tests named on the order are carried out or arranged with an independent laboratory.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing chemistry, tensile results and conductivity where specified, traceable to the cast and lot number.
- Pack and shipExport packing in sealed, moisture-protected wooden cases or on pallets, with interleaving where surfaces are critical, shipped by sea or air to your port or door.
References and standards
- SAE AMS 4141 – Aluminum Alloy Die Forgings, 7075-T73
- SAE AMS 4126 – Aluminum Alloy Forgings, 7075-T6
- ASTM B247 – Standard Specification for Aluminum and Aluminum-Alloy Die Forgings, Hand Forgings, and Rolled Ring Forgings
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
- ASM Handbook, Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
7075 aerospace aluminium (aluminum) forgings: FAQ
Should I order 7075 forgings in T6 or T73?
Order T6 only where maximum strength is needed and stress-corrosion risk is low. T73 or T7352 is the usual choice for structural fittings because of its much better stress-corrosion resistance.
What does T7352 mean?
The forging is solution treated, compressed about 1 – 5 % to relieve residual stress, and then overaged to the T73 condition.
Which specification covers 7075-T73 die forgings?
AMS 4141. AMS 4126 covers T6 forgings and AMS 4147 covers T7352 forgings; ASTM B247 is the general forging standard.
Is 7050 a better forging alloy than 7075?
For thick sections, yes: 7050-T74 keeps higher strength through the thickness with similar stress-corrosion resistance. For smaller forgings, 7075 is often adequate and more economical.
Can 7075 forgings be welded?
Fusion welding is not recommended because the weld zone cracks and loses strength. Forgings are joined mechanically.
Need 7075 forgings?
Send the drawing, temper, specification and quantity. Our team will confirm the forging route, certification and a delivered price.
