GB/T 14251-2026General technical requirements for metal containers for canned food (English PDF)

3.1 Metal container of canned food

Metal containers of empty cans (barrels) and filled cans for canned food made of tin-plated or chrome-plated thin steel sheets or aluminum alloy thin sheets.

3.2 Coated or laminated can

A metal can with a coating or lamination on its inner wall.

NOTE: including coated steel cans, painted aluminum cans, laminated steel cans, and laminated aluminum cans.

3.3 Two-piece drawn can

A packaging container formed by the combination of the can body (empty can) stamped and drawn from a single piece of thin metal sheet for the bottom and body, and a metal top cover.

NOTE: two-piece cans for canned food are generally two-piece drawn cans, with a height-to-diameter ratio of less than 1.

3.4 Splash

An object formed when molten metal is extruded and ejected from the weld seam due to excessively high welding temperatures, causing the center temperature of the welding spot to reach or exceed the melting point of steel.

3.5 Spatter spot

A granular substance formed after cooling when molten metal is extruded, ejected and splashed onto the tan wall during welding, due to excessively high welding temperatures, causing the center temperature of the welding spot to reach or exceed the melting point of steel.

3.6 Enamel rate value; ERV

Defects such as micropores and scratches on the surface of the inner coating/lamination due to factors such as raw materials and processing technology, etc.

NOTE: it is expressed as the conduction current value caused by the defects.

5.1 Raw and Auxiliary Materials

5.1.1 Tin-plated thin steel sheets

They shall comply with the provisions of GB/T 2520, Appendix A and relevant standards.

5.1.2 Chrome-plated thin steel sheets

They shall comply with the provisions of GB/T 24180 and relevant standards.

5.1.3 Aluminum alloy thin sheets

They shall comply with the provisions of GB/T 40319 and relevant standards.

5.1.4 Coated tin-plated or chrome-plated thin steel sheets

They shall comply with the provisions of GB/T 41899-2022 and relevant standards.

5.1.5 Laminated steel and laminated aluminum

They shall comply with the provisions of GB/T 43951 and relevant standards.

5.1.6 Copper wires

They shall comply with the provisions of Appendix B.

5.1.7 Other auxiliary materials

They shall comply with the requirements of relevant standards.

5.2 Quality of Empty Cans and Ends

5.2.1 Appearance quality

5.2.1.1 Empty cans shall be free from contamination, oil stains and peculiar odors, and shall be intact, free from deformation and obvious rust; except for plain tinplate cans, there shall be no exposed metal.

5.2.1.2 The main printed patterns and text shall be clear.

5.2.1.3 The scores on the key open cans shall be uniform, without faulty scores or welded-in key-open tongues.

5.2.1.4 The reinforcing ribs on the body shall be uniform, smooth, and intact, without disjoints, unevenness, wrinkles, or inconsistent depths; the welds at the reinforcing ribs shall be free from cracks.

5.2.1.5 The top and bottom ends shall be free from damage and obvious contamination, with no rust on the surface, no wrinkles or deformation on the hook edges, and no glue buildup, breaks, fishtail, or obvious bubbles in the sealant. The pull ring of the easy open end shall be free from damage or other defects. The sealing film of the easy peelable end shall have a smooth surface, and the transparent sealing film shall have uniform transparency, without obvious scratches or cracks. The pull handle shall be intact.

5.2.2 Weld quality

5.2.2.1 Welds shall be smooth and even, with uniform overlap and evenly connected welding spots. There shall be no cold welds, missing welding, pin holes, or punctures, and no obvious rust or splash.

5.2.2.2 The weld overlap shall meet the machining requirements for can manufacturing. The weld thickness shall not exceed 1.5 times the original plate thickness.

5.2.2.3 For sealed steel-lid cans. the sum of weld off-set and fishtail shall not exceed 0.5 mm.

For sealed aluminum-lid cans. the sum of weld off-set and fishtail shall not exceed 0.2 mm.

5.2.2.4 The weld seam of straight-wall cans shall be able to be torn off in one piece, without delamination or breakage.

5.2.2.5 Delamination and breakage shall not occur in the deformed areas of weld seam machining.

5.2.3 Seam quality

5.2.3.1 The seam shall be complete, without obvious scratches, rust, internal glue leakage, or external glue extrusion.

5.2.3.2 The seam shall be free from slip seam, cut-over, false seam, knocked-down flange, vee, droop and droop at juncture, jumped seam, fractured seam, sharp seam, double line, and other defects caused by pressure head and seam roller malfunctions.

5.2.3.3 The seam structure shall be agreed upon by both the supply-side and the demand-side, and the main indicator requirements shall conform to the requirements of Table 1 and Table 2.

5.2.8 Machining stability

After the test of 6.6, the inner walls of the empty can, and its top and bottom ends shall be free of pitting or linear corrosion spots.

NOTE: this test is not required for cans with plain tinplate inner walls.

5.2.9 Dry film performance of sealant

5.2.9.1 Uniformity

The deviation of the dry film weight of the sealant in any quadrant from the average dry film weight of the sealant in the other three quadrants should preferably not exceed 25%.

5.2.9.2 Moisture content

After the test of 6.7.2, the moisture content shall not exceed 5%.

5.2.9.3 Water resistance

After the test of 6.7.3, the sealant shall not exhibit curling, stickiness, peculiar odors or lacquering off.

5.2.9.4 Oil resistance

After the test of 6.7.4, the sealant shall not dissolve or become sticky, and it shall adhere well to the end surface.

NOTE: this test is not required for products without oil resistance requirements.

5.2.10 Quality of easy open ends and easy peelable ends

It shall comply with the provisions of relevant product standards.

5.3 Quality of Filled Containers

5.3.1 Appearance quality

Filled containers shall be intact, without leaks, external squeezing of compound, swelling, dents or peaking.

5.3.2 Inner wall quality

5.3.2.1 Inner wall of plain tinplate cans

Oxidation circles are permissible in the headspace area, but there shall be no pitting, abnormally rapid detinning, or perforation; no leaks, swelling, or internal squeezing of compound.

5.3.2.2 Inner wall of coated cans

There shall be no internal squeezing of compound. The coating film on the inner wall shall be intact, without blistering, peeling or lacquering off. There shall be no sulfide corrosion […]