Overview
EN ISO 14272:2016 - "Resistance welding - Destructive testing of welds - Specimen dimensions and procedure for cross tension testing of resistance spot and embossed projection welds" defines the specimen geometry and test procedure for measuring the tensile capacity of spot and projection welds in overlapping metallic sheets. The standard applies to sheet thicknesses from 0.5 mm to 3 mm and to welds with a maximum diameter of 7√t (t = sheet thickness in mm). The primary objective of the cross tension test is to determine the maximum tensile force (cross tension strength, CTS) the welded joint can sustain.
Key Topics and Requirements
- Scope and applicability: Spot and embossed projection welds in overlapping sheets, metallic materials, t = 0.5–3 mm, weld diameter ≤ 7√t.
- Specimen geometry: Test specimen consists of two rectangular coupons welded together; weld must be centered with a tolerance of ±1 mm.
- Clamping options:
- Specimens with drilled holes (for clamping bolts) or
- Specimens without holes using a hydraulic clamping system (no holes required).
- Test equipment: Tensile testing machines must meet ISO 7500-1; force measurement accuracy ≤ ±1%.
- Procedure:
- Clamp assembled specimen and apply tensile load until failure.
- Record cross tension force continuously; determine CTS as the maximum force.
- Tests performed at room temperature.
- Produce a load–displacement diagram for each test.
- Reporting: Test reports must reference ISO 14272:2016 and include welding process, welding conditions/equipment, material and condition, specimen dimensions, individual and statistical CTS values (kN), failure mode descriptions (plug, interfacial, etc.), weld diameters and any special remarks.
- Fixtures and accessories: Illustrative welding jigs and clamping devices (including hydraulic clamps) and anti-slip die treatments are described.
Applications and Users
EN ISO 14272:2016 is used by:
- Quality assurance and metallurgical laboratories performing destructive weld testing.
- Manufacturers in automotive, aerospace, appliance, and general fabrication sectors that rely on resistance spot and projection welding.
- Welding engineers and R&D groups validating joint strength, developing welding procedures, or comparing electrode/jig configurations.
- Certification bodies and standards committees for compliance testing and product qualification.
Practical benefits include consistent, repeatable measurement of joint tensile performance (CTS), standardized specimen preparation, and uniform reporting for comparative and contractual testing.
Related Standards
- ISO 7500-1 - Verification of static uniaxial testing machines (tension/compression).
- ISO 17677-1 - Resistance welding vocabulary (spot, projection and seam welding).
- ISO 14329 - Destructive tests - failure types and geometric measurements for resistance welds.