ISO 3376 Tensile strength and elongation test of leather

Information on the most widely used ASTM standards within the materials testing industry

Descriptions of the most prominent lSO standards within the materials testing industry

Standards including EN, DIN, JlS, and more

Mechanical testing of polymer materials in the automotive industry is directly related to the safety of components and the reliability of the entire vehicle. UnitedTest can cover mechanical performance testing for automotive interior and exterior parts, as well as functional components, adapting to automaker standards and providing comprehensive testing solutions including tensile, impact, and fatigue tests.

Mechanical testing in the battery industry determines the tensile and puncture resistance of core components such as separators and electrodes, directly affecting battery safety and cycle life. UnitedTest can cover full-dimensional mechanical testing of battery materials, compatible with national and international standards, and provide customized testing solutions.

Mechanical testing in the consumer goods industry determines product durability and safety, such as impact resistance for toys and fatigue resistance for home appliances, making it core to compliance and quality. UnitedTest can cover mechanical tests for all categories of consumer goods, including tensile, impact, and hardness tests, compatible with national and international standards, and offers customized testing solutions.

In the field of medical and biomedical sciences, mechanical testing determines the safety and compatibility of implanted devices and biomaterials, making it a core part of regulatory approval. UnitedTest can cover a full range of tests including tensile, fatigue, and wear tests, compatible with national and international standards, and provides customized biomechanical testing solutions.

Material strength is a course that most engineering fields are required to study in university education. This interesting course is very practical and makes use of testing equipment in the materials laboratory.

Mechanical testing of industrial products and components is essential to ensure their load-bearing, fatigue resistance, and impact resistance, directly preventing production accidents and ensuring stable operation of equipment. UnitedTest can cover a full range of tests including tensile, hardness, and fatigue, complying with national and international standards, and provides customized industrial mechanical testing solutions.

Mechanical testing in the plastic pipe industry determines ring stiffness, impact resistance, and tensile performance, directly preventing pipe bursts and deformation risks. UnitedTest can cover full-dimensional mechanical testing of pipes, complies with ISO,ASTM,EN et.c, international standards, and provides customized testing solutions.

In the construction engineering and building materials industry, mechanical testing determines the compressive and tensile properties of materials such as concrete and steel, which is core to ensuring the safety and durability of buildings. UnitedTest can cover the full range of building material mechanical tests, complies with ISO, ASTM international standards, and provides customized testing solutions for compressive, tensile, and other properties.

Mechanical testing in the food and beverage industry involves the compressive and tensile performance of packaging and the safety of food texture, directly ensuring storage, transportation safety, and the eating experience. UnitedTest can cover all-dimensional mechanical testing for packaging and food texture, comply with national and international standards, and provide customized testing solutions.

Mechanical testing in the packaging industry determines the packaging's resistance to compression, impact, and tension, directly ensuring the safety of contents during storage and transportation. UnitedTest can cover comprehensive mechanical testing for packaging, complying with ISO, ASTM Standards, and provides customized testing solutions for compression, drop, tear, and more.

Mechanical testing in the transportation industry concerns the load-bearing and fatigue resistance performance of core components such as vehicles, tracks, and containers, directly ensuring transport safety and equipment durability. UnitedTest can cover mechanical testing for all types of transportation materials, complying with national and international standards, and provides customized testing solutions including tensile, fatigue, and impact tests.

Metallurgical testing examines the properties of metallic materials to determine if a particular metal is appropriate for its intended use.

Testing of polymer materials covers mechanical, thermal, and chemical properties, verifying strength, heat resistance, composition, and ensuring product quality and compliance.

UnitedTest offer world-class testing solution in testing for polymeric materials, including elastomers, thermoplastics, composites, coatings, and structural adhesives in a variety of industries.

Testing of rubber and elastomers is used to assess the various properties and performance of materials under different conditions. This is crucial for ensuring the safety, functionality, and quality of rubber and elastomer products used in industries such as automotive, construction, consumer goods, and aerospace.

Conduct adhesive testing using various testing methods to determine their performance and characteristics in applications across multiple industries such as aerospace, automotive, construction, packaging, industrial, medical, and energy, thereby supporting application development and quality assurance.

UnitedTest supply machine and testing solution for tension, compression, fracture toughness, direct shear, triaxial and ultrasonic velocity are common concrete and rock testing applications.

UnitedTest has helped a number of companies involved in the wood, paper, cardboard, and corrugated industry with their testing needs. Our materials testing systems are capable of testing raw materials, components, and finished products.

UnitedTest testing system is trusted by leading medical device manufacturers, universities, and medical research laboratories worldwide. Whether testing tissues or bioresorbable materials, stents, or sutures, UnitedTest offers a variety of single-actuator and dual-actuator systems to meet your biomedical testing needs.

Mechanical testing in the textile fabric industry determines core properties such as fabric tensile strength, tear resistance, and wear resistance, directly affecting product durability and safety. UnitedTest can cover comprehensive mechanical tests for textiles, complying with national standards / ISO standards, and provides customized testing solutions including tensile, tear, and puncture tests.

The mechanical testing of industrial components directly determines the load-bearing, fatigue resistance, and wear resistance of the parts, helping to avoid equipment failure risks. UnitedTest can cover a full range of tests including tensile, hardness, and fatigue, is compatible with ISO/ASTM/GB standards, and provides customized mechanical testing solutions for industrial components.

Mechanical testing in the glass-ceramics industry determines core properties such as flexural strength, hardness, and fracture toughness, directly helping to avoid brittleness and failure risks. UnitedTest can cover comprehensive testing for flexural strength, hardness, and fracture toughness, compatible with national and ISO/ASTM standards, and provides customized testing solutions.

Tensile test evaluates material resistance to stretching, measuring strength/elongation critical for quality control. UnitedTest offers universal tensile testers (10-600KN) compliant with ASTM/ISO standards, providing tailored solutions for metals, polymers, medical & industrial materials.

Compression test assesses material resistance to compressive loads, measuring strength/deformation critical for quality validation. UnitedTest offers compression testing machines compliant with ASTM/ISO standards, providing tailored solutions for concrete, plastics, metals and industrial components.

Flexural & Bend tests evaluate material resistance to bending forces, measuring strength, stiffness and ductility for quality assurance. UnitedTest provides flexural testing machines (3-point/4-point bend) compliant with ASTM/ISO standards, offering tailored solutions for composites, plastics, metals and construction materials.

Torsion Test evaluates material resistance to rotational forces, measuring torsional strength/ductility critical for fasteners, insulators, shafts. UnitedTest offers torsion testers compliant with ASTM A938/ISO 16047, providing tailored solutions for automotive, aerospace, fastener industries.

Fatigue Test assesses material durability under cyclic loading, critical for predicting service life of industrial components. UnitedTest offers fatigue testing systems (axial/bending/torsion) compliant with ASTM E466/ISO 12106, providing tailored solutions for automotive, aerospace and manufacturing sectors.

Peel Test measures material adhesion strength by evaluating resistance to peeling forces, critical for adhesives, films, packaging. UnitedTest offers peel testers compliant with ASTM D903/ISO 8510, covering 90°/180° peel tests, and tailored solutions for packaging, automotive, textile industries.

Impact Test evaluates material resistance to sudden shock loads, critical for assessing toughness and fracture risk. UnitedTest offers impact testers (Charpy/Izod/fall weight) compliant with ASTM E23/ISO 148, providing tailored solutions for metals, plastics, glass and industrial components.

Tear & Shear Test evaluates material resistance to tearing and shearing forces, measuring critical strength parameters for quality control. Tear tests (Elmendorf/trouser/trapezoidal) assess resistance to crack propagation in films/fabrics, while shear tests measure resistance to parallel forces in joints/bolts. UnitedTest provides universal testing machines (10KN-600KN) with specialized fixtures for both tests, compliant with ASTM D624/D3164 and ISO standards, serving automotive, packaging and construction industries.

Hardness test measures material's resistance to permanent indentation, critical for quality control. UnitedTest offers universal hardness testers (Rockwell/Brinell/Vickers) compliant with ASTM/ISO standards, plus tailored hardness testing solutions for diverse industrial needs.

Biaxial/triaxial tests evaluate material performance under multi-axis loads, critical for biomaterials, metals and composites. UnitedTest provides compliant testing machines (ASTM/ISO) for planar biaxial, static/fatigue triaxial tests, with tailored solutions for industrial & biomedical needs.

Friction and wear tests assess material resistance to friction, abrasion and wear, critical for industrial material performance validation. UnitedTest offers tribometers compliant with ASTM G99/ISO standards, covering pin-on-disk, four-ball tests, and tailored friction & wear testing solutions for diverse industries.

Pressure test evaluates material/component resistance to static/dynamic pressure, critical for sealing, strength and safety validation. UnitedTest offers pressure testing machines compliant with ASTM/ISO standards, covering burst, hold-pressure tests, and tailored solutions for industrial, automotive & medical sectors.

Fire test assesses material flammability, heat resistance and fire-retardant performance, critical for safety compliance across industries. UnitedTest offers fire testing equipment compliant with ASTM/ISO/UL standards, providing tailored fire test solutions for building materials, plastics and industrial components.

Non-destructive Test (NDT) evaluates material/component integrity without damage, critical for safety & quality across industries. UnitedTest offers ultrasonic/X-ray/magnetic particle NDT equipment compliant with ASTM/ISO standards, plus tailored NDT solutions for aerospace, automotive & manufacturing sectors.

ISO 3376 Leather Tensile Strength & Elongation Tester | UnitedTest

ISO 3376, developed with IULTCS, specifies physical‑mechanical test procedures for leather to measure tensile strength, elongation under specified load and elongation at maximum force. UnitedTest produces ISO 3376 compliant testing machines for upper, lining, upholstery and automotive leather quality inspection.

ISO 3376 Leather‑Physical and mechanical tests‑Determination of tensile strength and percentage elongation

ISO 3376 provides a harmonised laboratory test method for measuring three critical mechanical properties of leather: tensile strength, percentage elongation under specified load, and percentage elongation at maximum force. Jointly published in cooperation with IULTCS, this standard covers nearly all leather varieties including upper leather, lining leather, upholstery leather, and automotive leather. Test results support raw material incoming inspection, product formulation comparison, and finished‑goods performance validation for footwear, furniture and automotive interior industries. UnitedTest designs and manufactures high‑precision ISO 3376 compliant testing machines to deliver repeatable tensile test results for leather material laboratories and production quality control.

Test Principle:

A dumbbell‑shaped leather test piece is stretched at a constant jaw‑separation rate. The test continues until force reaches a preset value or until the specimen breaks. Force and displacement data are continuously recorded to calculate tensile strength and elongation indicators.

Test Specimen Information

Shapes: Dumbbell-shaped, cut with press knives.

Standard size: overall length 110 mm, narrow section length l = 50 mm, width b = 10 mm, shoulder radius R = 5 mm, clamp width b₁ = 20 mm.

Large size (used when slippage occurs): overall 190 mm, l = 100 mm, b = 20 mm, R = 10 mm, b₁ = 40 mm.

Quantity: 6 pieces per sample — 3 with long axis parallel to backbone, 3 perpendicular to backbone.

Cutting: From grain side using press knife, after conditioning per ISO 2419.

Thickness t: mean of 3 readings per ISO 2589.

Soft leather note: width b taken as press-knife width.

ISO 3376 Tensile strength and elongation test of leather

Test Equipment of ISO 3376 Tensile strength and elongation test of leather:

Tensile testing machine:	- Force range suitable for test specimens; force‑measurement accuracy meets ISO 7500‑1. - Jaw separation speed: 100 mm/min ± 20 mm/min. - Capable of recording force‑elongation curves.
Clamp Fixtures	Minimum 45 mm length along load direction; mechanical or pneumatic clamping. Slippage inside jaws shall not exceed 1 % of original jaw‑to‑jaw distance under maximum test load.
Elongation recording device	either tracks jaw movement or uses sensors fixed on specimen gauge section.
Tools	1. Thickness gauge: compliant with ISO 2589 for leather thickness measurement. 2. Press cutting dies: for cutting standard/large dumbbell‑shaped specimens. 3. Vernier calliper: resolution 0.1 mm for width measurement.

Key Test Parameters and stipulations:

Jaw separation speed	100 mm/min ± 20 mm/min
Pre‑load (instrumental)	; ; no obvious elongation under pre‑load
Standard specimen jaw opening	50 mm ± 1 mm
Large‑size specimen jaw opening	100 mm ± 1 mm
Calliper resolution	0.1 mm
Force‑measurement class	ISO 7500‑1 Class 2

Slippage rule: If visible slippage occurs between specimen and jaw faces during test, discard this result and retest with a large‑size specimen cut by large press knife.

Single‑test multi‑index: Tensile strength, elongation under specified load and elongation at maximum force can be obtained in one continuous tensile run if pre‑load and initial‑length measurement are properly done.

Test Procedures of ISO 3376 Tensile strength and elongation test of leather:

Dimension measurement. Measure average width and average thickness of each test piece.
Mount specimen. Adjust jaw spacing, clamp specimen, ensure grain lies flat and specimen axis aligns with tensile direction.
Apply pre‑load. Apply specified small pre‑load and record initial gauge length L0.
Run tensile test at constant speed:

Record L1: jaw/sensor distance when force reaches specified load value (for elongation under specified load).
Record maximum force Fmax and corresponding length L2 at maximum force.
Continue stretching until specimen breaks.

Check slippage condition. Abandon result if slippage happens and repeat test.
Calculate results according to formulas.
Compile formal test report with required items.

Industry / Application Fields

Leather manufacturing & trading (tanneries, leather goods QC)

Footwear (upper and lining leather tensile/extend control)

Automotive interior (seat leather durability)

Furniture / upholstery (sofa leather stretch behavior)

Garment leather, belt & strap, saddle/harness where directional strength matters

Buyer specifications & dispute resolution (third-party lab testing against ISO)

ISO 3376 Tensile strength and elongation test of leather

Related & Similar Standards

ISO 3376	Leather — Determination of tensile strength and elongation
GB/T 46469	Leather—Physical and mechanical tests—Determination of tensile strength and percentage elongation
ASTM D2209	Standard Test Method for Tensile Strength of Leather
ASTM D2208	Standard Test Method for Breaking Strength of Leather by the Grab Method
SATRA TM 43	Tensile strength and extension at break of leather
ISO 3377-1	Leather - Physical and mechanical tests - Determination of tear load - Part 1: Single edge tear
ISO 3378	Leather - Physical and mechanical tests - Determination of resistance to grain cracking and grain crack index

Importance of This Test for Leather Material

Leather is natural fibre‑network material with obvious anisotropy (mechanical properties differ parallel vs perpendicular to backbone).

1. Quality benchmark: Tensile strength reflects leather’s capacity to resist pulling force; elongation indexes reflect stretchability and deformability under stress. These parameters directly predict service durability of leather goods, preventing unexpected tearing or excessive deformation during end‑use (e.g., shoes, apparel, bags).

2. Process feedback: Test data assess the influence of tanning, finishing and mechanical processing on collagen‑fibre network integrity. Defective tanning leads to low tensile strength and poor product service life.

3. Engineering reference: Provides mechanical parameters for product design, material selection and specification formulation. Separate‑direction test data reveal leather anisotropic nature for cutting‑pattern optimization in manufacturing.

4. Consistent comparison: Standardized test method enables repeatable, comparable lab results among different laboratories, supporting commercial‑trade acceptance and compliance verification for leather products.

Keywords: ISO 3376 leather tester,leather tensile strength test,leather percentage elongation measurement,IULTCS leather mechanical test,upper leather tensile tester,automotive leather testing equipment,upholstery leather lab machine,leather lining material strength test,footwear leather physical test,leather tensile elongation apparatus,leather material QC tester,leather maximum force elongation test

WDW Series Computer Control Electronic Universal Testing Machine made by UNITEDTEST range from 100N to 600KN load capacity with various models like single columns, table type, door frame type etc., is used to perform tension, compression, flexure/bending, shearing, peeling etc., test for metal and nonmetal specimens.

Snubbing and Capstan grips are all engineered to perform high strength tensile tests where the test samples are long compared to their cross-sectional area, such as wire, rope and strapping.

Q1. What is ISO 3376 and what does it measure?

A: ISO 3376:2020 (also published as IULTCS/IUP 6:2020) is the international standard for determining the tensile strength, percentage elongation at a specified load, and percentage elongation at maximum force of leather. It applies to all leather types—footwear upper, lining, upholstery, automotive, garment, etc.

Q2. Why is the ISO 3376 test important for leather?

A: Leather is anisotropic (stronger along the backbone than across it) and viscoelastic. This test tells you:

Whether the leather will tear or split under seam stress

How much it will stretch during lasting, upholstery wrapping, or stitching

If a tannage or finishing batch meets buyer specs (e.g., automotive OEMs, luxury brands)

Gives comparable MPa and % elongation numbers across labs and countries

Q3: Two specimen sizes: standard vs large test piece. When should I use large‑size dumb‑bell specimen?

A: Standard specimen (50 mm gauge length, 10 mm narrow width) is the first choice. Switch to large‑size specimen (100 mm gauge length, 20 mm narrow width) if visible specimen slippage occurs inside jaws during testing. Slipped test results must be discarded and retested with large die‑cut samples.

Q4: Why need test specimens in two directions (parallel & perpendicular to hide backbone)?

A: Leather shows strong anisotropy: collagen fibres run mostly along the backbone direction. Tensile strength and elongation results differ significantly between parallel‑to‑backbone and perpendicular‑to‑backbone directions. The standard requires testing both directions and reporting two sets of mean values separately in test report.

Q5: Can I get 3 indicators (tensile strength, specified‑load elongation, max‑force elongation) in one single test run?

A: Yes. If you apply correct pre‑load and record initial length L0 at test start, you can capture specified‑load elongation, maximum‑force elongation and tensile strength continuously within one test cycle without stopping machine between data points.

Q6. Why measure elongation at max force, not at break?

A: For some leathers the force drops before final rupture. ISO 3376 requires using E_max at F_max, not E_break, to avoid type-dependent variability.

Q7. What if the specimen slips in the jaw?

A: Reject the result and repeat with a large-size specimen and proper jaw face texture/pneumatic clamping.

Q8: Why choose UnitedTest ISO 3376 Leather Tensile Testing Machine?

A: UnitedTest is a professional manufacturer of ISO 3376:2020 (IULTCS/IUP 6) leather tensile testing machines, supplying complete hardware‑software solutions for leather physical‑mechanical laboratory testing. Our test systems fully comply with ISO 3376:2020 latest edition technical requirements, supporting tensile strength, percentage elongation under specified load and percentage elongation at maximum‑force measurement for all leather grades.

Our ISO 3376 leather tensile tester strictly follows standard parameters: constant jaw separation speed 100 mm/min ± 20 mm/min, force‑measurement accuracy conforming to ISO 7500‑1 Class 2. Built‑in configurable instrumental pre‑load function fulfils the 2020‑edition new requirement, eliminating leather specimen slack for accurate elongation results. Optional mechanical or pneumatic long‑size jaws (≥45 mm load‑direction length) effectively reduce specimen slippage during leather tensile tests. Software automatically calculates tensile strength (MPa), specified‑load elongation %, maximum‑force elongation %, and generates ISO 3376‑compliant test reports.

UnitedTest ISO 3376 test equipment serves leather factories, third‑party testing laboratories, footwear manufacturers, automotive upholstery suppliers, luggage & bag producers, furniture leather manufacturers and leather research institutes. The system supports both standard‑size and large‑size dumb‑bell leather specimens, handles test specimens cut parallel and perpendicular to hide backbone.

Besides ISO 3376 leather tensile test machines, UnitedTest also provides complementary leather‑testing instruments matching ISO 2418, ISO 2419, ISO 2589, ISO 3377‑2 and other IULTCS test standards, forming full‑range leather physical‑mechanical test solutions. If you need reliable ISO 3376:2020 IULTCS/IUP 6 testing machines for incoming‑goods QC, production‑line quality control, product certification or material research, contact UnitedTest for technical specification and quotation.

We offer customization to meet your specific needs. Our expert team will collaborate with you to develop the perfect product for you