ISO 3377-2:2025

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.