ISO 19958:2004 Overview
ISO 19958:2004 is an international standard specifying the test method for measuring the top piece retention strength in footwear heels. This standard focuses on determining the force required to detach the top piece from the underside of a shoe heel, ensuring quality and durability in footwear manufacturing. Applicable mainly to medium and high heels with pre-attached top pieces, the method accommodates various heel types except reinforced slender heels attached by steel spigots and built stacked heels.
Developed in collaboration between ISO/TC 216 Footwear and the European Committee for Standardization (CEN), ISO 19958:2004 provides manufacturers and testing laboratories with precise procedures to assess heel integrity, contributing to improved product safety, consumer satisfaction, and compliance with international quality standards.
Key Topics Covered
- Scope and Applicability: Testing applies to heels removed from shoes or as standalone heel pieces, with specific guidelines based on heel height and construction.
- Top Piece Retention Strength: Defined as the maximum force in Newtons required to pull off the heel top piece.
- Test Apparatus Requirements:
- Tensile testing machine compliant with EN ISO 7500-1 class 2.
- Additional tools including drills, bolts (M3 or M4), rods, or extensible cords.
- Sample Preparation:
- Detailed cutting, drilling, and bolt insertion procedures based on heel height (medium/high or low).
- Methods for attaching push-in, stapled, or nailed top pieces reproducibly.
- Test Methodology:
- Pulling the top piece off perpendicularly using a controlled force rate (15 N/s ± 5 N/s).
- Use of rods or cords to secure the heel during testing.
- Recording maximum and initial peak forces for thorough evaluation.
- Result Expression:
- Individual results recorded with maximum force values.
- Description of failure types and their locations.
- Test Reporting:
- Inclusion of comprehensive sample descriptions, testing method references, results, and test dates.
Practical Applications
ISO 19958:2004 is essential for:
- Footwear Manufacturers: To verify heel design, assembly methods, and material durability, ensuring that the top piece is securely attached and resistant to detachment under normal use.
- Quality Control Laboratories: For routine strength testing during production to maintain consistent product standards and reduce failure rates.
- Product Development: Assisting designers and engineers in selecting suitable materials and construction techniques that meet defined retention strength criteria.
- Compliance and Certification: Providing documented evidence of mechanical performance aligned with international norms, facilitating market access and consumer trust.
- Consumer Safety: Preventing premature or dangerous heel failures by establishing minimum retention strength thresholds.
Related Standards
- EN ISO 7500-1:1999 - Metallic materials - Verification of static uniaxial testing machines (tension/compression). This standard ensures the tensile testing machines used for measuring top piece retention strength meet accuracy and performance requirements.
- ISO/TC 216 Footwear Standards - Other ISO footwear standards address various performance and testing aspects, complementing ISO 19958:2004 in providing a comprehensive framework for footwear quality assurance.
- CEN/TC 309 Footwear Standards - Harmonized European standards corresponding to ISO/TC 216 provide regional alignment for footwear testing methods, including heel component analysis.
By implementing ISO 19958:2004 test methods, stakeholders in the global footwear industry can reliably evaluate heel top piece attachment strength, enhancing product durability and consumer confidence while facilitating compliance with international quality expectations.