Flat-rolled aluminum glossary
The words used at the plant, in purchasing and in trade compliance to order flat-rolled aluminum, explained in one or two lines. Each term links to the page with the details; figures come from Almexa's technical sheet or from the standard cited.
Updated 2026-10-21
From ingot to coil
- Primary aluminum
Aluminum produced by electrolysis of alumina at a smelter and sold as ingot. Mexico does not produce it: it imports it and processes it.
- P1020 ingot
Primary aluminum ingot of 99.7% minimum purity, the grade delivered under the London Metal Exchange aluminium contract. Almexa buys it already imported, from traders in Mexico.
- Aluminum scrap
Trimmings, offcuts and end-of-life parts that are melted again. Almexa uses more recycled aluminum in the alloys that allow it, from its own customers and from local scrap suppliers.
- Melting
The stage where ingot and scrap are melted in furnaces and the alloy chemistry is adjusted before casting. The Cuautitlán Izcalli plant has four melting furnaces.
- Direct chill (DC) casting
Semi-continuous casting: molten aluminum solidifies in a water-cooled mold and the slab keeps cooling under water jets as it descends. It is how Almexa makes its rolling slabs.
- Continuous casting (CC)
A process that solidifies aluminum directly into strip about 0.24 to 0.31 in (6 to 8 mm) thick, which goes to cold rolling without the hot mill. Almexa no longer uses it.
- Rolling slab
The rectangular block that comes out of DC casting and goes into the hot mill. At Almexa it is 14.6 in (370 mm) thick and 118 in (3,000 mm) long, in widths from 30.7 to 49.2 in (780 to 1,250 mm).
- Scalping
Milling the faces of the slab to remove the surface layer left by casting, before rolling.
- Homogenizing (preheating)
A long heat soak that evens out the slab's internal structure and brings it to hot rolling temperature.
- Hot rolling
Reducing the hot slab in back-and-forth passes on a reversing mill, down to a band 0.24 to 0.47 in (6 to 12 mm) thick.
- Hot band
The coil that comes off the hot mill, about 0.31 in (8 mm) thick in F temper. Almexa also sells it to re-rollers that take it to thinner gauges.
- Cold rolling
Room-temperature reduction that takes the 0.31 to 0.39 in (8 to 10 mm) band to final gauge, down to 0.0177 in (0.45 mm) at Almexa. It work-hardens the metal, so it is combined with annealing.
- Annealing
Heat treatment that softens cold-worked metal and restores its ductility. Full annealing gives O temper; partial annealing gives the H2X tempers.
- Slitting
Cutting a wide coil into narrower strips with circular knives. It produces strip and the exact width the customer orders.
- Cut-to-length (CTL)
A line that uncoils, flattens and cuts the coil into sheets of a set length, such as 48 × 96 in sheet.
- Tension leveling
Controlled stretching of the coil to remove edge waves and center buckles and improve flatness before cutting to sheet.
- Roll grinding
Grinding the mill rolls to keep their shape; consistent gauge and a good surface on the sheet depend on them.
- Circle blanking
Cutting circles or blanks from coil with a press and die. At Almexa circles are annealed after blanking so they are ready to draw.
Products and sizes
- Coil
Rolled sheet wound on itself, ordered by alloy, temper, gauge, width and weight. At Almexa, 0.0177 to 0.1575 in (0.45 to 4.0 mm) thick and 6.30 to 48 in wide, with a 20 in (508 mm) inside diameter.
- Sheet
Flat aluminum cut to size. Almexa makes it 0.0197 to 0.1575 in (0.5 to 4.0 mm) thick, up to 48 in wide and 120 in long; for example, 48 × 96 in sheet.
- Plate
Thick flat aluminum. ASTM B209 calls it plate from 0.250 in (6.3 mm); Almexa makes flat product over 0.157 in (4 mm), up to 13 in (330 mm).
- Circle (disc)
A round piece cut from coil for deep drawing or spinning. Almexa makes them 5.51 to 48 in (140 to 1,219 mm) in diameter and 0.0220 to 0.1575 in (0.56 to 4.0 mm) thick.
- Blank
A flat shape other than a circle, such as a square or a rectangle, cut to size for stamping or drawing.
- Strip
A narrow coil produced by slitting a wide one, for parts formed continuously.
- Inside diameter (ID)
The diameter of the coil's core opening, which must fit your uncoiler mandrel. At Almexa it is 20 in (508 mm).
- Outside diameter (OD)
The coil's overall diameter. With the ID and width it sets the coil weight; at Almexa it runs 39 to 46 in (990.6 to 1,168 mm).
- Mill width
The maximum width that comes off the mill before slitting: at Almexa, 48 in (1,219 mm) in 1000 and 3000 series and 36 in (914 mm) in 5000 series.
- Mill edge and slit edge
Mill edge is the edge as it comes off the rolling mill; slit edge is trimmed with knives to an exact width and a straight edge.
- Gauge
A number that indicates sheet thickness. Aluminum uses the Brown & Sharpe scale: 18 gauge is 0.0403 in (1.02 mm) and 24 gauge is 0.0201 in (0.51 mm). Ordering in decimal inches or millimeters avoids confusion.
- Scrap loss
Material lost when cutting: edge trim, leftover strip or the skeleton between circles. A good cutting plan reduces it.
- Theoretical weight
Weight calculated from dimensions and density; Almexa's charts use 2.71 g/cm³ (0.098 lb/in³). Actual weight varies with thickness tolerance.
- Aluminum density
Mass per unit volume: 2.71 g/cm³ for 1100, 2.73 for 3003, 2.72 for 3105 and 2.68 for 5052.
- F temper
As fabricated, with no control of mechanical properties. It is the condition of hot band.
Alloys and tempers
- Aluminum alloy
Aluminum with other elements in controlled amounts. Its four-digit number tells which: the first digit gives the series and the main alloying element.
- 1000 series
Aluminum of 99% or higher purity, very ductile and a good conductor. Almexa makes 1050, 1100 and 1350.
- 3000 series
Manganese alloys: stronger than the 1000 series, with good formability. Almexa makes 3003, 3004, 3104 and 3105.
- 5000 series
Magnesium alloys: higher strength and good corrosion behavior. Almexa makes 5005, 5052 and 5754, up to 36 in (914 mm) wide.
- Heat-treatable alloy
The 2000, 6000 and 7000 series, such as 6061, gain strength through heat treatment (T tempers). Almexa does not make them.
- 1100 aluminum
Aluminum of 99.00% minimum purity: very ductile, conducts heat well and resists corrosion, with low mechanical strength.
- 3003 aluminum
An alloy with 1.0 to 1.5% manganese: the general-purpose sheet, stronger than 1100 and easy to form.
- 3105 aluminum
An alloy with manganese and magnesium, the most common for roofing, gutters and sheet for painting.
- 5052 aluminum
An alloy with 2.2 to 2.8% magnesium and higher strength; Almexa makes it in O and H3X tempers, such as H32.
- 1350 aluminum
Electrical-grade aluminum of 99.50% minimum purity, for conductors.
- Temper
The designation that follows the alloy, as in 3003-H14, and tells whether the metal was strain hardened, annealed or stabilized.
- O temper
Annealed: the softest, most ductile condition. It is the one ordered for deep drawing and spinning.
- H14 temper
Strain hardened by cold rolling to half hard, with no annealing afterward. It sits between O (annealed) and H18 (full hard).
- H24 temper
Strain hardened beyond the target and then partially annealed to half hard: strength similar to H14, with more elongation.
- H32 temper
Strain hardened and stabilized by a low-temperature heat treatment to quarter hard. It is the most common temper for 5052.
- Strain hardening
The strength aluminum gains when it is rolled or formed cold; in exchange, it loses elongation.
- Elongation
How much a test specimen stretches before breaking, in percent. The higher it is, the more the metal can be formed without tearing.
- Yield strength
The stress at which the metal stops springing back and deforms permanently.
- Tensile strength
The maximum stress a test specimen withstands before breaking. It appears on the lot's mill test report along with yield strength and elongation.
- Grain size
The size of the metal's crystals. Coarse grain leaves an orange-peel surface after drawing or spinning.
- Earing
Waves on the rim of a drawn part caused by sheet that does not behave the same in every direction; it is controlled through rolling and annealing.
- Deep drawing
Forming a circle into a hollow part, such as a pot or a cup, with a press and die in one or more draws.
- Metal spinning
Forming a circle that turns on a lathe against a mandrel, pushed by a tool. In Mexico it is called rechazado, entallado or repulsado.
- Stamping
Cutting and forming parts with a press and die. Automotive stamping uses 5052 and 5754, from the 5000 series.
Quality and standards
- Mill test report (MTR)
The mill's document with the chemical composition and mechanical properties of a lot. Almexa provides it with every order.
- ASTM B209
The US specification for aluminum sheet and plate: composition and mechanical properties by alloy and temper; it refers to ANSI H35.2 for tolerances.
- ANSI H35.2
The dimensional tolerance standard for aluminum mill products (thickness, width, length and flatness), published by The Aluminum Association.
- Thickness tolerance
The allowed difference between actual and nominal thickness; under the standard it depends on alloy, thickness and width.
- Flatness
How flat the sheet lies. Edge waves and center buckles are measured on receipt and corrected by leveling.
- ISO 9001
The quality management system standard. Almexa has been certified by Intertek since 2010; the current certificate is valid until February 4, 2027.
- Traceability
Being able to follow a lot from casting to the delivered coil or circle. It is the basis for handling a claim and for documenting origin.
Price and trade
- LME
London Metal Exchange: the exchange that sets the public price of primary aluminum, in US dollars per metric ton. It is the base of sheet pricing.
- FAB (conversion cost)
What the mill charges to turn metal into coil, sheet or circles. It is the only part of the price that differs between suppliers.
- FOB, CIF and DDP
Delivery terms (Incoterms). FOB: price at the port of origin. CIF: includes freight and insurance to the destination port. DDP: delivered to your plant with duties paid.
- Duty (tariff)
A tax on imports. Since January 1, 2026 Mexico charges 5% to 50% on 1,463 tariff lines from countries without a trade agreement; on the sheet and coil lines Almexa makes, 10% to 30%.
- HS heading
The code that classifies goods for duties. Aluminum plates, sheets and strip over 0.2 mm (0.0079 in) thick fall under heading 7606.
- Antidumping duty
An extra duty on dumped imports. In Mexico, for example, it applies to aluminum cookware from China.
- USMCA (T-MEC)
The trade agreement between Mexico, the United States and Canada. A finished part enters duty free if it meets its rule of origin, which your trade compliance team determines; Almexa provides the origin documentation for each lot.
- Section 232
The US tariff on aluminum and aluminum derivatives, up to 50% in 2026, which requires importers to declare the country of smelt and cast of the metal.
- Country of smelt and cast
Country of smelt is where the primary aluminum was first produced; country of cast is where the metal was last cast into slab or strip before rolling. For Almexa products the country of cast is Mexico; the country of smelt is backed by the ingot producer's certificates.
- Automatic Aluminum Import Notice (AAA)
The notice in which the direct importer declares to Mexican authorities the aluminum it imports, including its country of smelt. Almexa buys metal that is already imported.
- Re-roller
A company that buys hot band or coil and rolls it again to thinner gauges.
- Service center
A company that buys coil from the mill and slits, levels and stocks it to sell by the piece or on short lead times.
- Distributor
Resells aluminum from one or more producers. It holds stock and delivers fast, but it does not manufacture: it cannot change the alloy or the temper of a lot.
- Rolling mill
A plant that melts, casts and hot and cold rolls aluminum. Almexa is Mexico's aluminum rolling mill, in Cuautitlán Izcalli.