What Beverage Can Tab Stock Requires
Aluminum coil for beverage can tab stock is the flat rolled material that becomes the end of a can and the tab that opens it. The duty is demanding: the coil must be stiff enough to hold internal pressure, ductile enough to be scored and formed without cracking, chemically stable against beer, fruit juice and carbonated drinks, and clean enough to accept the internal lacquer and external print that carry the brand. In practice these requirements are met by two magnesium-bearing grades, 5052 and 5182, supplied in work-hardened tempers and in coil form for high-speed presses.
5052 Aluminum Coil
5052 is an aluminum-magnesium alloy with magnesium typically between 2.2% and 2.8%, plus a small chromium addition that refines grain structure and improves resistance to stress corrosion.
Corrosion resistance: strong performance in salt water and in mildly chemical environments, which is essential for a food-contact closure
Strength: medium strength with a good yield-to-tensile ratio, sufficient for can components that must not deform in handling
Formability: readily stamped, bent, drawn, rolled and welded without special tooling
Typical service: can and bottle end components, closures and general tab stock where balanced strength and formability matter more than peak load
5182 Aluminum Coil
5182 carries more magnesium, generally 4.0% to 5.0%, with manganese and a trace of chromium as the secondary additions. The higher magnesium content lifts strength well above 5052 while retaining good corrosion behaviour.
Higher strength: suited to end stock and tab stock that is scored, necked and opened under load
Corrosion resistance: excellent for beverage contact and for humid storage conditions
Machinability and forming: performs reliably in high-speed presses and in the multi-stage tooling used for pull tabs
Typical service: can ends, easy-open ends and tabs, especially where pressure resistance and stiffness are the limiting requirements
Composition and Typical Properties
| Item | 5052 | 5182 |
|---|---|---|
| Principal alloying elements | Magnesium 2.2% to 2.8%, chromium 0.15% to 0.35% | Magnesium 4.0% to 5.0%, manganese 0.20% to 0.50% |
| Iron (max) | 0.40% | 0.35% |
| Silicon (max) | 0.25% | 0.20% |
| Copper (max) | 0.10% | 0.15% |
| Typical tensile strength, O temper | About 190 MPa | About 275 MPa |
| Typical tensile strength, hard temper | About 230 to 260 MPa | About 390 MPa |
| Typical yield strength, hard temper | About 195 to 215 MPa | About 350 to 365 MPa |
Values are typical for coil supplied to general industrial sheet specifications such as ASTM B209, EN 485 and GB/T 3880, with composition limits following GB/T 3190 for the corresponding grades. Final property requirements are agreed with the rolling mill for each press line, because tooling, scoring depth and line speed all affect the temper that performs best.
Performance Requirements and Quality Control
Six characteristics decide whether a coil performs in the press and in the market:
Sealability: the surface must be flat and clean enough for a reliable double seam that prevents leakage and keeps carbonation in
Pressure resistance: end stock must withstand the internal pressure of carbonated drinks without excessive bulging
Corrosion resistance: no reaction with the beverage and no staining under humid or chilled storage
Formability and machinability: consistent behaviour in stamping, scoring, necking and welding operations
Light weight: low density keeps transport and storage costs down and supports downgauging
Recyclability: used ends and tabs return to the melt with high recovery value
Because tab stock is converted at very high speed, gauge tolerance, flatness, surface finish and cleanness are controlled batch by batch. Dirt, rolled-in oxide or oil residue causes scoring defects and lacquer adhesion failures, so mills supply degreased coil, often with a thin protective film, and test each batch for mechanical properties and surface defects before shipment.
Frequently Asked Questions
Q: What is aluminum coil for beverage can tab stock?
It is flat rolled aluminum supplied in coil form that is punched, scored and formed into can ends and opening tabs. It combines pressure tightness, corrosion resistance and high-speed formability.
Q: Why are 5052 and 5182 used for can tab stock?
Both are aluminum-magnesium alloys with good corrosion resistance and formability. 5052 offers balanced medium strength, while 5182 delivers higher strength and stiffness for ends and tabs that must hold pressure.
Q: What is the magnesium content of 5052 and 5182?
5052 contains about 2.2% to 2.8% magnesium, and 5182 contains about 4.0% to 5.0% magnesium together with manganese and a trace of chromium.
Q: Which grade is stronger, 5052 or 5182?
5182 is clearly stronger. In the annealed condition 5052 is around 190 MPa in tensile strength against roughly 275 MPa for 5182, and in hard tempers the gap is about 260 MPa against 390 MPa.
Q: What tempers are supplied for tab stock?
Work-hardened tempers such as H32 and H34 for 5052 and H19 or H48 for 5182 are common, selected to match the scoring and forming sequence of the press line.
Q: Can can tab stock be recycled?
Yes, and it is a valuable scrap stream. Aluminum remelting needs only a fraction of the energy used to make primary metal, and used ends and tabs are routinely collected and recycled.
