Leather - Determination of flex resistance - Part 1: Flexometer method
Material
Industry
Our test laboratory performs testing according to DIN EN ISO 5402‑1 under accredited conditions. This international standard defines a method for determining the bending and long-term flex resistance of leather. Its purpose is to objectively assess how well flexible leather types—including their surface finishes—can withstand repeated bending without developing premature cracks, breaks, or other damage. The standard applies to all flexible leathers with a thickness of less than 3 mm.
Test principle and procedure
Testing according to DIN EN ISO 5402‑1 is carried out using a flexometer, where a standardized leather specimen is clamped between two grips. A defined crease line is formed, and the testing device subjects this line to repeated bending cycles, moving the crease along the length of the specimen. This simulates repeated mechanical stress, as occurs in practical use during sitting, handling, or movement of leather surfaces.
Specimens can be tested in either a dry or pre-moistened state to reflect different use conditions. After a specified number of bending cycles, the sample is evaluated for cracking, material fatigue, and surface changes.
Significance of results
The results provide critical information on the durability and usability of leather. They support material selection, quality control, product development, and comparative studies, particularly for automotive interior components, upholstery leather, apparel, and technical applications where repeated bending occurs and long service life is required.
The DIN EN ISO 5402‑1 flexometer test is also widely used for failure analysis, as it reliably reflects leather fatigue behavior.