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Tinplate inspection catches problems before they reach the can line. Consequently, incoming QC checks six categories on every coil. Furthermore, the mill certificate tells you what the mill measured; your own inspection confirms it. Here are the items, test methods, and typical acceptance criteria.

Inspection Checklist

Item	Test method	Typical acceptance
Tin coating weight	XRF or strip method	Matches spec (e.g. 2.8/2.8 g/m² ±10%)
Adhesion	Bend and tape test	No peeling or flaking
Surface quality	Visual under angled light	No rust, roll marks, deep scratches
Thickness	Micrometer at 5 points	±0.01 mm
Flatness	Straightedge	<2 mm wave in 1 m
Oil weight	Extraction and weighing	8–12 mg/m² palm oil

1. Tin Coating Weight

XRF measures tin weight non-destructively. Furthermore, the strip method (chemical dissolution) gives a reference measurement. Consequently, XRF screens every coil; the strip method verifies disputed lots. Acceptance: ±10% of specified weight.

2. Adhesion

Bend a 180-degree sample around a mandrel of equal thickness. Then apply and peel tape. If tin flakes off, adhesion fails. Consequently, this test catches poor reflow or dirty plating.

3. Surface Quality

Unwrap one sample sheet. Hold it at 45 degrees under a bright light. Tilt slowly. Watch for scratches, roll marks, rust spots, and oil stains. Furthermore, check the coil edge—rust almost always starts there.

4. Thickness and Flatness

Measure thickness at the center and four corners. Furthermore, lay the sheet on a flat table and check for wave. A wavy sheet feeds unevenly into the press. Consequently, reject coils with >2 mm wave in 1 m.

5. Salt Spray (Optional)

For critical applications, run a salt spray test per ASTM B117. Typically, 48 hours without red rust confirms adequate passivation. Furthermore, food can stocks usually skip this test because the mill already validates it.

Related Inspection Standards We Apply

We apply the same incoming inspection logic to other sheet products:

• C11000 / T2 Copper Plate ships with thickness, flatness, and visual inspection report.
• C12200 / TP2 Copper Tube gets eddy current and hydraulic pressure test.

Specify Your Inspection Requirements

Tell us your acceptance standard (ASTM A624, EN 10203, GB/T 2520). We will ship with the matching inspection report.

• Email: vera.liang@ztwysteel.com
• Location: Xishan District, Wuxi, Jiangsu, China
• Supply range: tinplate substrates, copper plate/tube, nickel alloys, electrical steel
• Documentation: MTC + coating weight report + visual inspection certificate
• Standards: ASTM A624, EN 10203, GB/T 2520

We reply within one working day.