ISO 13937-4:2000

Overview - ISO 13937-4:2000 (Double tear / tongue test)

ISO 13937-4:2000 is the international test method for measuring the tear force of fabrics using the tongue‑shaped (double tear) specimen. The method quantifies the force required to propagate two parallel tears from a pre-cut “tongue” when pulled in the direction of the cuts. It is mainly intended for woven fabrics and some nonwovens, and is performed on constant‑rate‑of‑extension (CRE) tensile testing machines.

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Key topics and technical requirements

• Specimen geometry: Tongue‑shaped specimens with two parallel slits joined by a transverse slit; specimens are cut in both warp and weft directions. An end‑of‑tear mark is placed at 25 ± 1 mm from the uncut end.
• Sampling and quantity: From each laboratory sample, cut at least five specimens per direction (warp and weft); avoid selvedges, folds and non‑representative areas.
• Machine type and settings:
  • CRE tensile testing machine only (one clamp stationary, the other moves at constant speed).
  • Rate of extension: 100 ± 10 mm/min.
  • Gauge length: 100 ± 1 mm.
  • Data acquisition frequency: at least 8 samples per second if electronic.
• Apparatus accuracy: Meets class 1 requirements of ISO 7500-1 where maximum force error ≤ ±1% and jaw separation error ≤ ±1 mm. If class 2 equipment is used, it must be reported.
• Clamping and jaws: Jaws must hold specimens without slippage or damage; recommended jaw width ≈ 200 mm (minimum not less than specimen width).
• Conditioning: Preconditioning and test atmosphere per ISO 139.
• Result evaluation:
  • Tear force is determined from force peaks on the force/extension trace.
  • Two calculation routes: manual (chart) or electronic - results from different methods are not directly comparable.
  • Manual method: divide tear length into four equal parts, discard first quarter, and use peaks from the remaining three (see standard for full procedure).

Applications and who uses it

• Quality control and product specification for woven fabrics used in apparel, upholstery, industrial textiles and technical textiles.
• Comparative testing in R&D to evaluate fabric constructions, finishes and treatments that affect tear resistance.
• Conformance testing for suppliers, manufacturers, test laboratories and procurement teams requiring consistent tear‑resistance data.
• Useful where directional tear behavior (across warp or across weft) must be characterized.

Related standards

• ISO 139 (conditioning atmospheres for testing)
• ISO 7500-1 (verification of tensile testing machines)
• ISO 10012-1 (metrological confirmation of measuring equipment)
• Other EN/ISO 13937 parts:
  • Part 1 - Elmendorf (ballistic pendulum)
  • Part 2 - Trouser (single tear)
  • Part 3 - Wing (single tear)
• For nonwovens/coated fabrics: ISO 9073-4 and ISO 4674 (other trapezoidal and coated fabric methods)

This concise summary highlights what ISO 13937-4:2000 covers, its main technical requirements, and practical uses for textile testing and quality assurance. For implementation, refer to the full standard for figures, specimen patterns and example calculations.