EN ISO 7799:2000

Overview

EN ISO 7799:2000 - Metallic materials - Sheet and strip 3 mm thick or less - Reverse bend test specifies a laboratory method to determine the ability of thin metallic sheet and strip to undergo plastic deformation when subjected to alternating bending. The procedure (originally ISO 7799:1985) uses a rectangular test piece clamped at one end and repeatedly bent through 90° in alternating directions over a cylindrical support of specified radius. The standard applies to sheet and strip up to 3 mm thickness and can be applied to aluminium and its alloys only after prior agreement.

Key topics and requirements

• Scope: Evaluation of plastic deformation capacity for sheet and strip ≤ 3 mm thickness.
• Test principle: Repeated reverse bending (90°) in opposite directions to simulate cyclic bending strain.
• Specimen arrangement: Rectangular test piece held at one end (cantilever style).
• Bending support: Bending is performed over a cylindrical support with a specified radius (as defined in the standard).
• Materials covered: General metallic materials; aluminium and its alloys require specific agreement before application.
• Purpose of measurements: Determine suitability for forming processes and detect susceptibility to cracking or failure under alternating bend loads.

Note: The standard defines test geometry, support radius, and procedural parameters; consult the full EN ISO 7799:2000 text for exact dimensioning and acceptance criteria.

Applications

• Quality control and acceptance testing for sheet and strip materials used in forming and bending operations.
• Characterizing formability and bend fatigue resistance for manufacturing processes such as stamping, bending, and deep drawing.
• Comparative testing between production batches or suppliers to ensure consistent material performance.
• Material selection in product design where repeated or reverse bending is expected (e.g., flexible metal components, housings, brackets).

Who uses this standard

• Materials testing laboratories and metallurgical test houses.
• Manufacturers and processors of thin metallic sheets and strips (steel, stainless steel, other alloys).
• Quality assurance teams for automotive, appliance, aerospace and general metal fabrication industries.
• Procurement, R&D and engineering teams specifying mechanical testing and formability requirements.

Related standards

• ISO 7799:1985 (original international document)
• EN ISO 7799:2000 (European adoption)
• ICS classification: 77.040.10 - Mechanical testing of metals

Keywords: reverse bend test, EN ISO 7799:2000, ISO 7799, sheet and strip testing, metallic materials, formability test, aluminium alloys, mechanical testing, quality control.