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Adhesion testing answers one question: will the coating stay on the metal? Consequently, every paint, lacquer, and plating shop needs a repeatable test. Furthermore, the wrong test gives false confidence. Here are the three methods shops actually use, and when each one fits.

Method 1: Cross-Hatch Tape Test

This is the most common shop-floor test. Procedure:

1. Cut a 1 mm × 1 mm grid through the coating.
2. Apply standard tape (3M 610).
3. Pull off at 90 degrees.
4. Rate per ASTM D335B: 0 = no loss, 5 = full removal.

Consequently, a rating of 0 or 1 passes. Furthermore, this test suits paint, powder coat, and lacquer on flat surfaces.

Method 2: Pull-Off Test

This test measures the force in MPa needed to pull a dolly off the coated surface. Procedure:

1. Glue a 20 mm dolly to the coated panel.
2. Cure the adhesive.
3. Pull perpendicular with a pull-off tester.
4. Record failure force and mode (adhesive vs cohesive).

Consequently, this test gives a number, not just a pass/fail. Furthermore, it suits critical coatings on structural steel and aerospace parts.

Method 3: Bend Test

For thin sheet and tinplate, the bend test is fastest. Bend the sample 180 degrees around a mandrel of equal thickness. Then inspect for cracking or flaking. If the coating stays intact, adhesion passes. Consequently, can makers use this test on lacquered tinplate every shift.

Surface Preparation Decides the Result

No adhesion test matters if the surface is dirty. Consequently, shops follow a standard cleaning sequence:

1. Degrease with alkaline cleaner or solvent.
2. Acid etch or blast to the required profile.
3. Rinse and dry immediately.
4. Coat within hours.

Furthermore, touch the cleaned surface only with gloves. Oil from one fingerprint ruins the bond.

Substrates We Ship Ready for Coating

We deliver clean, controlled stock that coats well:

• C11000 / T2 Copper Plate mill-clean and PVC-film protected.
• H13 / SKD61 Mold Steel soft-annealed and pre-machined.
• C12200 / TP2 Copper Tube internally cleaned and end-capped.

Specify Your Coating System

Tell us what coating you will apply (paint, powder, lacquer, PVD). We will confirm surface condition and packing to give your coater the best starting point.

• Email: vera.liang@ztwysteel.com
• Location: Xishan District, Wuxi, Jiangsu, China
• Supply range: copper plate/tube, mold steel, nickel alloys, tinplate, wear plate
• Documentation: MTC with chemistry, hardness, and surface condition
• Packing: PVC film, VCI paper, wooden pallets

We reply within one working day.