5052 Aluminium Alloy and Its Tempers
Alloy 5052 is an aluminium-magnesium alloy with 2.2–2.8 % magnesium, 0.15–0.35 % chromium, and additions limited to 0.45 % combined silicon and iron, 0.10 % copper, 0.10 % manganese and 0.10 % zinc. Magnesium is the solid-solution strengthening element, while chromium controls grain structure and resists stress corrosion. With a density of about 2.68 g/cm³, 5052 offers the highest fatigue strength of the common non-heat-treatable alloys and outstanding resistance to seawater and industrial atmospheres, which is why it is a standard choice for aerospace auxiliary systems, marine structures and fuel handling equipment. Sheet and plate are covered by ASTM B209, with aerospace procurement frequently referencing AMS-QQ-A-250/8 and the related AMS 4015, 4016 and 4017 specifications for the O, H32 and H34 tempers.
Temper Designations and Mechanical Properties
The H temper system describes strain hardening: H32 is strain hardened and stabilised to a quarter-hard condition, H34 to a half-hard condition, and O is the fully annealed, softest and most formable state.
| Temper | Typical tensile strength | Typical yield strength | ASTM B209 tensile range | ASTM B209 yield, min |
| O | 195 MPa | 90 MPa | fully annealed condition | reported per lot |
| H32 | 228 MPa | 193 MPa | 31.0–38.0 ksi (214–262 MPa) | > 23.0 ksi (159 MPa) |
| H34 | 262 MPa | 214 MPa | 34.0–41.0 ksi (234–283 MPa) | > 26.0 ksi (179 MPa) |
| H36 | 276 MPa | 241 MPa | 37.0–44.0 ksi (255–303 MPa) | > 29.0 ksi (200 MPa) |
| H38 | 290 MPa | 255 MPa | > 39.0 ksi (269 MPa) | > 32.0 ksi (221 MPa) |
Available manufacturing range for the alloy covers coil and sheet from 0.2 mm to 6 mm, plate from 6 mm to 250 mm, widths up to roughly 2 650 mm for sheet and 3 800 mm for wide plate, and lengths up to 20 m or cut to order. Surface options include bright, polished, hairline, brushed, sand-blasted, checkered, embossed and etched finishes, and coil can be supplied with black and white, blue or transparent protective film in 50 µm and 80 µm thicknesses.
Aerospace and General Applications
Aerospace: fuel and oil tanks, hydraulic and pneumatic tubing, fuel and oil lines, instrument panels, ducting, cowlings, brackets, firewall and non-structural fairings, and small satellite or probe shells where formability and weldability matter more than peak strength.
Marine: hull plating for light craft, superstructures, deckhouses, gangways and tank work exposed to salt water.
Transport: truck bodies, bus panels, tanker shells and railway interior components.
General industry: pressure vessels, refrigeration equipment, television and communication towers, signage, and appliance panels.
It is important to separate this list from primary load-bearing airframe structure. Where damage tolerance and static strength dominate, the industry uses heat-treatable alloys such as 2024 or 7075 in the appropriate tempers; 5052 is selected for its corrosion resistance, fatigue performance, formability and weldability in secondary and fluid-handling roles.
Fabrication Notes
5052 is the most weldable of the high-magnesium alloys and is joined by TIG and MIG with 5356 filler, keeping heat input moderate to limit magnesium loss and soften the heat-affected zone. It can be cold formed readily; the minimum bend radius in the H32 and H34 tempers is approximately one to two times thickness for a 90° bend across the rolling direction, and tighter radii require the O temper or an intermediate anneal. Annealing is carried out near 345 °C. Machining is acceptable although the alloy is gummy and benefits from sharp, high-rake tooling. Anodising produces a clear or greyish protective film but is not as bright as that obtained on lower-magnesium alloys, so decorative work often prefers a different alloy while anodising for corrosion protection is entirely satisfactory. Crevice protection and correct drainage design still matter, because 5052 is not immune to pitting in stagnant seawater.
Quality Control and Common Mistakes
Three errors recur in procurement. First, ordering H32 or H34 without confirming the required ASTM B209 tensile window, then receiving material at the low end of the range that fails a stiffness or load calculation. Second, assuming that 5052 plate and 5052 sheet share identical properties, when plate from 6 mm upwards is produced by hot rolling and can differ in temper designation and properties from cold-rolled coil. Third, accepting a certificate that names the alloy but not the temper, heat number, dimensions and mechanical results. A compliant package states alloy and temper, thickness and width, heat or lot number, tensile and yield results, elongation, and the specification under which the material was produced.
Frequently Asked Questions
Q: What is the magnesium content of 5052 aluminium?
A: 2.2–2.8 %, which is the main solid-solution strengthening element in the alloy.
Q: What does the H32 or H34 temper mean?
A: Strain hardened and stabilised to quarter-hard (H32) or half-hard (H34) condition, giving higher strength than the O temper with some loss of formability.
Q: Which standards cover 5052 sheet and plate?
A: ASTM B209 for general sheet and plate, with AMS-QQ-A-250/8 and AMS 4015, 4016 and 4017 used for aerospace tempers.
Q: Can 5052 be used for primary aircraft structure?
A: It is normally used for fuel tanks, lines, ducting and secondary structure; heat-treatable alloys such as 2024 and 7075 are chosen where high static strength is required.
Q: Where is 5052 plate available in?
A: Coil and sheet from 0.2 mm to 6 mm with widths up to about 2 650 mm, and plate from 6 mm to 250 mm in widths up to about 3 800 mm.
Q: How is 5052 welded?
A: By TIG or MIG with 5356 filler, controlling heat input to limit softening of the heat-affected zone.
