A high-end aluminium forging is a part shaped by plastic deformation from a certified heat-treatable alloy, with controlled grain flow, a specified temper and full inspection records. This guide explains which alloys, forging routes, tempers and tests separate aerospace, defence and energy-grade forgings from commodity parts, and what to put on your enquiry so the supplier quotes the right product.
Every forging starts as a cast ingot or extruded billet that is heated and squeezed, hammered or rolled into shape. What lifts a forging into the high-end category is not the press but the control around it: a registered alloy with tight chemistry, a forging plan that puts the grain flow where the loads are, a defined heat treatment, and inspection that proves the inside of the part is sound.
Forging closes the porosity left from casting, breaks up coarse intermetallic particles and stretches the grains into a fibrous structure that follows the outline of the part. When that grain flow runs along the main stress paths, fatigue life, fracture toughness and resistance to stress corrosion are noticeably better than in the same shape machined from plate or bar, where the grain runs in one direction regardless of geometry.
That is why landing-gear components, wing and fuselage fittings, rocket rings and bulkheads, missile cases, high-pressure flanges, forged wheels and suspension arms are forged rather than cast or hogged from a block. The trade-off is cost and lead time: dies, forging passes and heat treatment cycles all add up, so forging pays off where failure is expensive or weight reduction is valuable.
Most high-end orders fall into one of the families below. Sizes depend heavily on the alloy, because high-strength 2xxx and 7xxx grades need thicker sections to be quenched evenly and have narrower forging temperature windows than 6xxx grades. Send your finished-part envelope and we will advise the forging route and the machining allowance to plan for.
| Form | How it is made | Typical uses |
|---|---|---|
| Forged block (hand forging) | Ingot upset and drawn on an open-die press, worked in all three directions | Machined fittings, mould bases, thick structural parts where plate is not thick enough |
| Disc / pancake | Billet upset between flat dies, sometimes saddle-forged | Wheel blanks, flanges, sputtering backing plates, valve bodies |
| Forged bar and shaft | Billet drawn out on open dies, round, square or stepped | Large-diameter shafts, axles, rollers, stock for machined parts |
| Seamless rolled ring | Pierced doughnut rolled between a mandrel and main roll | Rocket and launcher rings, bearing races, flanges, gear blanks, pressure-vessel rings |
| Forged and back-extruded tube | Billet pierced and drawn, or cup back-extruded on a press | Large hollow cylinders, hydrogen and gas-storage shells, thick-wall pipe |
| Forged flange | Ring- or die-forged, then machined to ASME or EN pattern | Pipeline, cryogenic and chemical plant connections |
| Closed-die (impression) forging | Billet pressed into matched dies, flash trimmed | Brackets, arms, knuckles, wheels, aircraft fittings in volume |
For dedicated product pages see rolled rings, forged blocks, discs and forged tube and fittings.
Forging alloys come from four families. Copper-bearing 2xxx alloys keep strength at elevated temperature; 5xxx alloys are non-heat-treatable and chosen for corrosion and weldability; 6xxx alloys are the general-engineering workhorses; 7xxx alloys give the highest strength. The values below are typical room-temperature properties from published Aluminum Association and ASM data, not specified minimums. Design to the minimums in the governing specification, which fall as section thickness grows and differ between longitudinal and transverse directions.
| Alloy and temper | Typical tensile (MPa) | Typical yield (MPa) | Elongation (%) | Why it is chosen |
|---|---|---|---|---|
| 2014-T6 | 483 | 414 | 13 | High strength, good forgeability; heavy-duty aircraft and truck parts |
| 2024-T4 | 469 | 324 | 19 | Fatigue resistance and toughness; aircraft fittings |
| 2219-T62 | 414 | 290 | 10 | Weldable, strong from cryogenic to about 300 °C; launch-vehicle tanks and rings |
| 2618-T61 | 441 | 372 | 10 | Retains strength at 150 – 250 °C; pistons, compressor and turbo parts |
| 4032-T6 | 379 | 317 | 9 | High silicon, low expansion, wear resistance; forged pistons |
| 5083-O | 290 | 145 | 22 | Seawater resistance and weldability; marine and cryogenic flanges and rings |
| 6061-T6 | 310 | 276 | 12 | Balanced strength, corrosion resistance and cost; general and marine forgings |
| 7075-T6 | 572 | 503 | 11 | Very high strength; highly loaded fittings |
| 7075-T73 | 505 | 435 | 13 | Over-aged for stress-corrosion resistance at some loss of strength |
Two further alloys deserve mention. 7050 in T74 and T7452 tempers is the standard choice for thick aerospace forgings, because its lower quench sensitivity keeps strength in the centre of heavy sections while the over-aged temper resists stress-corrosion cracking. 6082 is the European counterpart of 6061 for forged automotive suspension parts and structural fittings. For both, use the specification minimums and the mill certificate rather than generic figures, because properties depend strongly on section size.
The workpiece is shaped between flat or simple dies by successive blows or press strokes. No part-specific tooling, so it suits prototypes, one-off large parts and blocks, bars and discs. Grain refinement comes from upsetting and drawing in several directions. Shapes are simple and the part needs generous machining stock.
Heated billet is pressed into matched dies; excess metal escapes as flash and is trimmed. Dies cost money but give near-shape parts, consistent grain flow and less machining, so the cost per part falls quickly with volume.
A pierced preform is rolled between a driven roll and an idler mandrel while axial rolls control height. The grain runs around the circumference, which is exactly where hoop stresses act in rings, flanges and bearing races.
A punch drives into a contained billet so metal flows backwards around it, forming a cup or tube with a sound, worked wall. Used for large hollow parts and thick-wall cylinders.
Tighter die design, controlled die temperature and close-tolerance billets produce thin webs and small draft angles, cutting machining time on high-volume parts such as wheels and suspension arms.
Lower-temperature forging of softer alloys (1xxx, 3xxx, 6xxx) for small parts with excellent surface and tolerance, such as electrical connectors and fasteners. See our cold forging guide.
| Decision factor | Open-die forging | Closed-die forging |
|---|---|---|
| Part shape | Simple: blocks, discs, bars, rings | Complex, with ribs, bosses and pockets |
| Quantity | One-offs to small batches | Medium to high volume |
| Tooling cost | Very low | High; amortised over the run |
| Machining allowance | Large | Small |
| Dimensional repeatability | Lower | High |
| Grain flow | Good, generally aligned to the main axis | Follows the part contour |
Heat-treatable forgings are solution treated, quenched and aged. The quench locks in residual stress, which matters because high-end forgings are usually machined heavily afterwards. Forging-specific tempers deal with this:
Ask for heat treatment to AMS 2770 or AMS 2772, with furnace uniformity surveys and quench-delay control, when the part is for aerospace or defence. For 7xxx forgings, electrical conductivity measured by eddy current is used alongside hardness to confirm that the over-ageing step actually happened.
A forging quote depends on the forged envelope, not the finished part. If you send a machined-part drawing, we work back to a forging shape with machining stock, then confirm the alloy, temper, specification and inspection class with you before pricing.
| Check | What it shows | Typical reference |
|---|---|---|
| Chemical analysis | Alloy conforms to registered limits, heat by heat | Aluminum Association limits, EN 573-3 |
| Tensile tests | Strength and elongation in the directions the spec requires (L, LT, ST) | ASTM B557, ASTM B247, EN 586-2 |
| Ultrasonic inspection | Internal voids, inclusions and laps through the whole volume | AMS-STD-2154 or ASTM B594, class AAA to B |
| Macroetch / grain flow | Flow lines follow the contour; no laps, folds or flow-through | First article and periodic sectioning |
| Hardness and conductivity | Correct temper and heat-treatment response | ASTM E10, AMS 2658 |
| Penetrant inspection | Surface cracks and laps after machining | ASTM E1417 |
| Dimensional report | Forged and machined dimensions against drawing | EN 586-3 or customer drawing |
All of this is summarised on an EN 10204 3.1 certificate tied to the heat and lot numbers stamped on the part. For programmes that need it, third-party witness of testing can be arranged. Specify the ultrasonic class early: class AA or AAA can dictate a more conservative forging reduction and adds inspection time.
| Criterion | Forging | Casting | Machined from plate or bar |
|---|---|---|---|
| Internal soundness | Porosity closed by deformation | Possible shrinkage porosity and inclusions | Sound, but grain runs one way |
| Fatigue and toughness | Highest, grain follows contour | Lowest | Good, but weak in short-transverse direction |
| Shape complexity | Moderate | Highest, internal cavities possible | Limited by machining access and waste |
| Material use | Good near-shape | Very good | Poor for deep pockets, much becomes swarf |
| Tooling cost | Medium to high (closed-die) | Medium to high | None |
| Best for | Safety-critical, cyclically loaded parts | Complex housings, lower stress | Prototypes and small batches |
Compared with other metals, aluminium forgings weigh roughly a third of an equivalent steel forging (2.70 versus 7.85 g/cm³) and about 60 % of a titanium-alloy forging, while giving good corrosion resistance and easy machining. Steel and titanium win where strength at high temperature or very high absolute load is the priority; magnesium is lighter still but less resistant to corrosion. Metline supplies the aluminium forgings in such comparisons, not the steel or titanium alternatives.
Wing and fuselage fittings, landing-gear parts, engine mounts, rotorcraft transmission housings and swash plates, launcher separation rings, adapter rings, domes and bulkheads, mostly in 2014, 2219, 7050 and 7075.
Armoured-vehicle wheels and track parts, missile cases and interstage rings, weapon-mount brackets, often in 7xxx and 5083 for weldable protection.
Cryogenic and LNG flanges in 5083 and 6061, gas-storage cylinder shells, large rings and forged tubes for power equipment where conductivity and corrosion resistance matter.
Forged wheels, control arms, steering knuckles, brake calipers, pistons in 4032 and 2618, mostly closed-die forged 6061 and 6082.
Cranks, triple clamps, stems, hubs and suspension parts where weight and fatigue life drive design.
Hinges, pulleys, couplings, gear blanks and hydraulic manifolds that need forged toughness without the weight of steel.
7075-T6 has the highest typical strength of the common forging alloys, around 570 MPa tensile. For thick aerospace parts, 7050-T74 or T7452 is usually preferred because it keeps strength through heavy sections and resists stress-corrosion cracking much better than 7075-T6.
For the same alloy and temper the static strength is similar, but a forging has grain flow that follows the shape, closed porosity and better short-transverse properties. That gives longer fatigue life and higher toughness, which is why safety-critical parts are forged.
Both reach peak-aged strength. T652 adds a small cold compression after quenching that relieves residual stress, so the part moves much less during heavy machining. Choose T652 (or T7352 for 7xxx) for parts with deep pockets or thin walls.
Open-die suits simple shapes, large sizes and small quantities because it needs no part-specific dies. Closed-die forging costs more to set up but produces near-shape parts with consistent grain flow and less machining, so it wins at medium to high volumes.
Chemical analysis, tensile tests in the specified directions, ultrasonic inspection to AMS-STD-2154 at the agreed class, hardness and conductivity for heat-treated tempers, grain-flow macroetch on first articles and a dimensional report, all recorded on an EN 10204 3.1 certificate.
Yes. Forgings can be supplied as forged, rough machined or machined to drawing, with optional shot peening, sand blasting or anodising, and shipped worldwide with full certification.
Send the drawing, alloy, temper and inspection class. Our team will recommend the forging route and reply with certification details and a delivered quote.
