ISO 17132:2007

Overview

ISO 17132:2007 - Paints and varnishes - T-bend test - specifies a standardized method for evaluating the flexibility and adhesion of an organic coating on a metallic substrate by bending a coated test panel and observing cracking or loss of adhesion. The method can be used as a pass/fail check or to determine the minimum bending diameter (or equivalent) at which cracking does not occur. Typical conditioning and test conditions are given (e.g., 16 h at 23 ± 2 °C and 50 ± 5 % RH).

Key topics and requirements

• Test principle: Bend coated panels 180° (coated side outside) around mandrels, spacer panels, or by repeated folding; inspect for cracking or flaking.
• T‑bend rating: Expressed as the minimum number of panel thicknesses (mandrel method), number of spacers (spacer method) or number of additional folds (folding method) at which no failure occurs.
• Apparatus & inspection:
  • Vice with smooth jaws; optional mandrels or uncoated spacer panels.
  • Magnifying glass (×5 to ×10) for visual inspection.
  • Adhesive tape (6–10 N/25 mm per IEC 60454‑2) for tape pull-off adhesion check.
• Specimen preparation: Use representative samples and standard test panels prepared per ISO 1513 and ISO 1514; measure dry film thickness per ISO 2808.
• Conditioning & test environment: Default conditioning and testing at (23 ± 2) °C and (50 ± 5) % RH unless otherwise agreed.
• Evaluation: Examine bends immediately (excluding 5 mm from panel edges). Use tape pull-off or magnification to detect loss of adhesion. Report whether failures were cracking only, adhesion loss only, or both.
• Supplementary information: Test panel material/shape, coating application and drying/stoving details, film thickness, and whether the test is classification or pass/fail should be specified by contracting parties.

Applications and users

ISO 17132:2007 is used to:

• Verify flexibility and adhesion of paints, varnishes and coil coatings on metallic substrates.
• Confirm compliance with contractual or specification requirements (quality control, incoming inspection).
• Support product development and comparative performance testing in R&D. Primary users:
• Coating and paint manufacturers
• Quality control and materials testing laboratories
• Metal fabricators and coil coaters
• Specifiers, procurement teams and standards bodies

Related standards

• ISO 1513, ISO 1514, ISO 2808 (sample, panel prep, film thickness)
• Other cracking/detachment tests: ISO 1519, ISO 1520, ISO 6272, ISO 6860
• Comparable national standards: ASTM D4145, EN 13523‑7, JIS G 3312

Keywords: ISO 17132:2007, T‑bend test, paint flexibility, adhesion test, metallic substrate, pass/fail test, minimum bending diameter, film thickness.