1100 is the workhorse unalloyed grade for sheet metal work that must be formed deeply, welded easily and resist mildly corrosive service. It is not the strongest aluminium, but it is one of the most predictable to fabricate, and that is why it stays in specification lists for chemical equipment and heat-transfer parts.
1100 contains a minimum of 99.00% aluminium with 0.05-0.20% copper, the deliberate addition that separates it from 1050 and allows it to be supplied with guaranteed strength in the strain-hardened tempers. Composition limits are set in ASTM B209 and in GB/T 3190-2020; mechanical properties of sheet and strip appear in GB/T 3880.2-2012, EN 485-2 and ISO 6361-2, and dimensions and tolerances in GB/T 3880.3.
| O | 90 | 35 | 30-45% | |
| H12 | 110 | 97 | 12% | |
| H14 | 124 | 117 | 9% | |
| H16 | 138 | 131 | 6% | |
| H18 | 152 | 145 | 5% |
These are typical values for commercial production rather than specification minima; ASTM B209 sets minimum limits per temper and thickness, and buyers should quote the temper explicitly because the strength range across the H series is almost double from H12 to H18.
Applications That Suit 1100
Chemical process vessels and tank linings, heat exchanger plates, deep-drawn cookware and holloware, nameplates and signage, reflectors, ventilation ducting and electrical busbar where conductivity matters more than strength. In these duties the grade is selected for elongation, thermal conductivity of about 220 W/(m.K) in the annealed condition, and the absence of alloying elements that would reduce electrical conductivity.
1100 in the O temper can be drawn, spun and embossed to shapes that crack in any heat-treatable alloy. It welds by TIG and MIG with 4043 or 1100 filler and needs no post-weld heat treatment, and it brazes and solders well because the oxide is thin and easily fluxed. Anodising produces a clear, bright finish, and the grade takes chemical conversion coatings and paint without special preparation, although it is soft and marks easily on handling.
Q: Is 1100 stronger than 1050?
A: Yes. The 0.05-0.20% copper addition in 1100 raises typical tensile strength to about 124 MPa in H14 against roughly 95 MPa for 1050 in the same temper, while both remain non-heat-treatable.
Q: Can 1100 be heat treated to a higher strength?
A: No. 1100 is not age hardenable, so strength can only be raised by cold work. Annealing is used to soften it for forming, not to strengthen it.
Q:
A: The O temper. Drawing is normally done in the annealed condition and intermediate anneals are performed between successive draws to restore elongation.
Q: Does 1100 corrode in seawater?
A: It resists fresh water and mildly corrosive atmospheres but pits in chlorides. For marine service, 5052 or 5083 should be specified instead.
Q: What is 1100 sheet supplied as standard?
A: Cut-to-length sheet and coil in thicknesses from about 0.2 mm to several millimetres, in mill finish or with a protective film, with mill certificates stating chemistry, temper and mechanical test results by heat number.