The bottom is integral
In a common two-piece beverage can, the cylindrical wall and closed bottom are formed from one metal disk. The separate second piece is the top.
Episode V019 · Source record
Why Soda Cans Have a Domed Bottom
A common two-piece beverage-can body has an integral bottom whose center curves inward into the can. That dome helps the thin bottom resist unwanted pressure-related deformation, while the surrounding standing ring gives the finished can a stable support path on a flat surface.
- Research lock
- August 12, 2026
- Evidence stack
- 8 source records · 8 direct links
- Visual proof
- Two selected permission-cleared can specimens
ONE SELECTED CAN UNDERSIDE
DOME IN. RING DOWN.
EXACT COMMERCIAL PROFILES VARY
The sourced answer
One connected bottom profile does a pressure job and a support job.
The dome changes resistance
The inward-curved center helps the thin bottom resist unwanted pressure-related deformation as part of a complete profile.
The ring defines support
The annular standing ring remains the lowest region, so the dome can stay recessed while the can rests on a nearly circular contact path.
Original specimen proof
The real cans establish contact geometry. The diagrams explain the bounded mechanism.
H1 and C1 show the same broad relationship with visibly different dimensions: the central region remains above the support plane while the surrounding ring reaches it. Their appearance is not used to rank strength, safety, or pressure performance.
Owned or permission-cleared footage. Ordinary handling only.
- H1 is one selected slim sparkling-water can
- C1 is one selected 12 oz can with its branding concealed
- Initial full-can footage used unopened specimens
- Empty H1 macro footage followed normal opening, rinsing, and drying
- No can was cut, crushed, dropped, heated, frozen, punctured, or artificially pressurized
- Public derivatives remove private metadata and conceal production codes
The cross-sections, load arrows, forming sequence, and performance panels are original conceptual graphics. They reproduce no patent drawing, paper figure, report art, standards table, brand asset, or competitor frame.
Forming and tradeoffs
The geometry must survive manufacture and more than one performance criterion.
Blank, cup, body
Flat sheet is blanked and cupped, then drawing and ironing lengthen and thin the wall while the bottom remains integral.
Profile variables
Dome depth, diameter, surrounding radii, material thickness, material strength, and forming history can change bottom behavior.
Different limits
Growth, impact response, dome reversal, stable standing, usable volume, and material use are related design questions, not one universal score.
Direct source library
Trace every public claim.
Each note states what its reference supports and where the evidence stops. External sources open in a new tab.
Anatomy and support
The dome and standing ring are connected parts of one bottom
These design records document integral can bodies, inward central domes, annular rims, and surrounding standing surfaces. Each record describes particular designs rather than every commercial can.
S01Locked 2026-08-12
US6132155A
Google Patents record of a U.S. patent application
The record describes a drawn-and-ironed body with an integral end wall, an annular rim as the lowest region, and a central dome. It links profile changes with pressure resistance and possible lightweighting for a selected target, not a universal result.
S04Locked 2026-08-12
WO2021058998A1
Google Patents record of a WIPO publication
This design-specific record documents one metal container body and bottom formed as one piece, with an inward central dome and an outward surrounding ring that defines a standing surface. Its dimensions are not generalized.
Performance and variation
Growth, impact response, reversal, material, and geometry interact
The patent records supply design vocabulary and documented examples. The independent experiment has a narrow steel-can boundary. None of these sources establishes one ideal profile or pressure value for every can.
S02Locked 2026-08-12
US20050194388A1
Google Patents record of a U.S. patent application
The application treats bottom growth, drop response, and buckle as separate criteria and describes a nose region that defines the circumferential stand. Its test values and profile dimensions belong to the documented family.
S03Locked 2026-08-12
US7472800B2
Google Patents record of a U.S. patent
This is the grant in the same family as S02, not independent corroboration. It also describes blanking, cupping, redrawing, ironing, and forming the dome and other bottom features in a body maker.
S05Locked 2026-08-12
US7398894B2
Google Patents record of a U.S. patent
The record connects bottom performance with profile design, gauge, internal pressure, contents, carbonation, temperature, and ambient pressure. Its background and embodiments do not define one industry-wide threshold.
S06Locked 2026-08-12
Optimum design of beverage-can ends and its experimental verification
Journal of Materials Processing Technology
Utsunomiya and Nishimura tested a defined drawn-and-ironed steel can of approximately 53 mm body diameter made from 0.18 mm sheet. Their profile and material findings are not transferred as exact results for ordinary aluminum cans.
Manufacturing and standards
The shape must work with a forming process and a package specification
These industry records support the bounded manufacturing sequence and the fact that current package formats use controlled dimensions. They do not identify the exact bottom profile of either filmed specimen.
S07Locked 2026-08-12
Life Cycle Assessment of North American Aluminum Cans
The Aluminum Association
The industry report describes coil feeding, blanking and cupping, forming, ironing, trimming, washing, coating, necking, flanging, and quality control in a North American aluminum-can system. It is used for process sequence only.
S08Locked 2026-08-12
Beverage Can Standards
Can Manufacturers Institute
CMI publishes one current 202 beverage-can and end specification example with an express disclaimer. It supports format variation and controlled dimensions, not a universal dome mechanism or pressure target.