--- title: Aluminium Sheet Grades: 1050, 5052, 5083 and 6082 description: 1050 is soft and easy to bend, 5052 is the all-rounder, 5083 is marine grade, 6082 is strong but bends poorly. Here's how to pick an aluminium sheet grade. url: https://ctrlcut.co.za/blog/aluminium-grades-for-sheet-metal published: 2026-10-22 updated: 2026-10-22 --- # Aluminium sheet grades explained: which alloy to use for your part For most sheet metal parts in South Africa, the choice comes down to four aluminium grades: **1050** for soft, easy forming, **5052** as the all-rounder, **5083** for marine and heavy-duty work, and **6082** when you need strength in plate. Pick by how the part will be bent, welded, and used, not by which number sounds strongest. The grade decides whether a bracket bends cleanly or cracks along the fold, and whether a boat fitting lasts or pits. The number is only half the story, too: the temper after it (H14, H32, T6) matters as much. Below we explain how the numbering works, what each common grade is good at, and how they behave on the press brake. ## How aluminium grades are numbered Wrought aluminium alloys use a four-digit number. The first digit tells you the main alloying element, which tells you a lot about how it behaves. - **1xxx**: essentially pure aluminium, 99% or more. Soft, very formable, very corrosion-resistant, low strength. - **2xxx**: copper. Strong, used in aerospace, but poorer corrosion resistance. Rare in general sheet metal work. - **3xxx**: manganese. A bit stronger than pure aluminium and still easy to form (3003 is the common one). - **5xxx**: magnesium. Good strength without heat treatment, excellent corrosion resistance, weldable. The marine series. - **6xxx**: magnesium and silicon. Heat-treatable for higher strength, used for extrusions and plate. - **7xxx**: zinc. Very strong, used in aerospace and high-performance parts, generally not for welded sheet work. The 1xxx, 3xxx, and 5xxx series get their strength from cold work (rolling). The 6xxx series gets it from heat treatment. That difference shows up when you bend and weld them. ## What the temper code means The letters and numbers after the grade tell you its condition. The common ones on sheet and plate: - **O**: annealed, fully soft. Bends easily, lowest strength. - **H14**: work-hardened to about half hard. Common on 1050 sheet. - **H32**: work-hardened and stabilised, about quarter hard. Common on 5052. - **H111, H116, H321**: variants seen on 5083. H116 and H321 are the tempers usually specified for marine work. - **T6**: solution heat-treated and artificially aged. Full strength for 6xxx alloys, and the hardest to bend. So "5052" alone isn't a full specification. "5052-H32" is. ## The common grades compared These are the grades South African suppliers commonly stock as sheet and plate. | Grade | Type | Strength | Formability | Weldability | Corrosion resistance | Typical uses | |---|---|---|---|---|---|---| | 1050 (H14) | Pure aluminium | Low | Excellent | Very good | Very good | Covers, flashings, signage, reflectors, light-duty parts | | 5052 (H32) | Aluminium-magnesium | Medium | Very good | Good | Excellent, including marine air | Enclosures, brackets, tanks, vehicle and trailer parts | | 5083 | Aluminium-magnesium | Medium to high | Good | Very good | Excellent, including seawater | Boat parts, marine fittings, truck bodies, pressure vessels | | 6082 (T6) | Aluminium-magnesium-silicon | High | Poor in T6 | Good, but softens near weld | Good | Structural plate, base plates, machined and flat parts | ## Which grade for which job? ### 1050: soft and cheap to form 1050 is the one to use when the part is mostly about shape, not strength. It bends easily, takes tight radii, and has a clean, bright surface. Think of a 1 mm cover, a flashing, a decorative panel, or a sign. Its weakness is dents. It's soft, so it marks and deforms if knocked. ### 5052: the sensible default If you're not sure, 5052 is usually a safe answer. It's noticeably stronger than 1050, still bends well with a radius around 1× thickness, welds well, and resists corrosion in marine air. A 2 mm 5052 enclosure or bracket is a very typical part. ### 5083: marine and heavy-duty 5083 is the strongest of the common non-heat-treated grades, with excellent resistance to seawater and industrial chemicals. It's the standard choice for boat hulls and fittings, and it keeps its strength well after welding, which suits welded structures. In soft tempers it bends much like 5052; harder tempers and thicker plate want a more generous radius. ### 6082: strong, but plan your bends 6082-T6 is the strongest of the four and machines well, which is why it's common as plate. But in the T6 temper, it doesn't like tight bends. As a starting rule, plan an inside radius of 1.5–3× thickness or more, and avoid bending parallel to the rolling direction. Welding also softens the metal next to the weld, losing a significant part of its T6 strength. If your part is mostly bent sheet, 5052 or 5083 is often the better choice. > If you need a bent aluminium part to be strong, 5083 or 5052 bent at a sensible radius is usually a better bet than 6082-T6 bent tightly and cracked on the outside of the fold. ## How the grades bend Bending is where the grade really shows. Rules of thumb for inside bend radius: - **1050 and 3xxx (soft tempers):** about 1× thickness, sometimes less - **5052-H32:** about 1× thickness - **5083:** about 1× thickness in soft tempers, more in harder tempers and thicker plate - **6082-T6:** 1.5–3× thickness or more Grain direction matters too. Aluminium cracks more easily when the bend line runs parallel to the rolling direction of the sheet. On harder grades, orient bends across the grain where you can, or note the grain direction on the drawing. Our post on [bending aluminium without cracking](https://ctrlcut.co.za/blog/bending-aluminium-without-cracking) goes deeper on radii and grain. Our [CNC bending](https://ctrlcut.co.za/cnc-bending) service bends aluminium as well as steel, and the grade and temper on your drawing tell us which tooling and radius to use. ## Corrosion, mixing metals, and coating All four grades resist atmospheric corrosion well, thanks to aluminium's natural oxide film. The 5xxx series is the pick near the sea. Watch out when aluminium touches other metals. Stainless bolts, steel brackets, or copper in contact with aluminium in wet conditions can make the aluminium corrode at the joint. Isolate them with washers or sealant. Our guide to [galvanic corrosion](https://ctrlcut.co.za/blog/galvanic-corrosion-mixing-metals) explains why. All the common grades can be powder coated for colour. If you're still deciding whether aluminium is right at all, compare it in [aluminium vs steel sheet](https://ctrlcut.co.za/blog/aluminium-vs-steel-sheet). ## What to put on your quote Give the grade and temper if you know them (for example, "5052-H32, 2 mm"), the quantity, and any bending, welding, or coating. If you don't know the grade, say what the part does and where it lives, and choose "Not sure yet". [Start a quote for CNC bending](https://ctrlcut.co.za/quote?service=cnc-bending) and add laser cutting and finishing to the same order. ## Frequently asked questions ### What is the most common aluminium sheet grade? For general sheet metal work, 5052 and 1050 are very common, with 5083 widely used for marine and heavy-duty parts. 6082 is common as plate rather than thin sheet. The best choice depends on whether the part needs to bend, weld, or carry load. ### Which aluminium grade is best for bending? Soft grades bend best. 1050 and 3003 in soft tempers, and 5052-H32, can typically be bent at an inside radius of about one material thickness. Heat-treated grades like 6082-T6 need much larger radii and crack more easily. ### What is marine grade aluminium? Marine grade usually means 5xxx-series alloys, especially 5083 and 5052, which resist seawater and salt air well. For boat building, 5083 in H116 or H321 temper is the common specification. ### Is 6082 aluminium weldable? Yes, 6082 can be welded with standard aluminium processes. The catch is that the heat softens the metal near the weld, so it loses part of its T6 strength there. Designers usually allow for that or choose a 5xxx grade for welded parts. ### Can Ctrl Cut bend aluminium sheet? Yes. Aluminium is one of the materials we work with, along with mild steel, stainless steel, and 3CR12, and we can laser cut, bend, weld, and coat it on one order. Put the grade and thickness on the quote, or say you're not sure and we'll help you choose. --- Get a quote: https://ctrlcut.co.za/quote?service=cnc-bending Contact: [ctrlcutsa@gmail.com](mailto:ctrlcutsa@gmail.com) · [+27 60 960 9722](tel:+27609609722)