Overview
ISO 3377-2:2025 - Leather - Physical and mechanical tests - Part 2: Determination of double edge tear load defines a standardized laboratory method for measuring the tear strength of leather using a double edge (Baumann) tear. Applicable to all types of leather, this third-edition ISO/IULTCS method specifies specimen preparation, equipment, test procedure and reporting so results are comparable across laboratories and supply chains.
Key Topics and Requirements
- Test principle: A rectangular test piece with a specified hole is torn between the turned-up ends of two holders in a tensile testing machine; the maximum force during tearing is recorded.
- Apparatus:
- Tensile testing machine with force measurement accuracy of at least ±2% (Class 2 per ISO 7500-1) and a jaw separation speed of 100 mm/min ±20 mm/min.
- Steel test piece holders and a press knife capable of cutting the test piece in one operation (per ISO 2418).
- Thickness gauge as specified in ISO 2589.
- Sampling & specimen preparation:
- Cut six test pieces from each sample: three with the long side parallel to the backbone and three perpendicular.
- Condition specimens per ISO 2419 before testing.
- Measure thickness at the prescribed location and use the mean value for strength calculations.
- Procedure & calculations:
- Mount the specimen on holders, tear using the tensile machine, record maximum force for each specimen.
- Calculate mean tear load (N) from three specimens per direction.
- Optional: calculate mean tear strength in N/mm by dividing mean tear load by mean thickness.
- Reporting: Test report must reference ISO 3377-2:2025 and include mean thickness, mean tear loads (parallel and perpendicular to backbone), overall mean, optional N/mm strength, conditioning atmosphere, deviations, date and sample identification.
Applications and Users
ISO 3377-2:2025 is used by:
- Leather tanneries and quality control laboratories to verify tear resistance.
- Footwear, upholstery, automotive and leather-goods manufacturers for material selection and specification compliance.
- R&D teams evaluating processing, finishes, or treatments that affect tear strength.
- Certification bodies and procurement teams requiring reproducible tear strength data for supplier acceptance.
Practical benefits include reliable comparison of leather grades, informed material choices for end-use performance, and consistent test reporting for supply-chain communication.
Related Standards
- ISO 2418 - Specimen cutting and positioning
- ISO 2419 - Conditioning of leather specimens
- ISO 2589 - Thickness measurement
- ISO 7500-1 - Calibration/verification of tensile machines
- Other parts of the ISO 3377 series and IULTCS/IUP 8 methods
Keywords: ISO 3377-2:2025, leather tear strength, Baumann tear, double edge tear, tear load test, tensile testing machine, N/mm, specimen conditioning.
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