October 2026: New Standard Improves Fastener Coating Assessment for Mechanical Components

Enhancements in fastener durability and reliability take center stage in the latest release for the mechanical components industry. Published in October 2026, CEN ISO/TS 25393:2026 marks a significant development for anyone sourcing, specifying, or producing coated fasteners. This new standard, the only one published this cycle for the sector, serves as an essential complement to CQI-11, closing longstanding gaps in process assessment and property validation for coated fasteners used across a variety of demanding applications. For manufacturers, chemical suppliers, electroplaters, and end-users, these changes promise higher performance, better traceability, and renewed confidence in mechanical fastening systems.

Overview / Introduction

Mechanical systems and components—such as fasteners—form the backbone of countless industrial sectors, from automotive and machinery to electronics and infrastructure. In this context, the reliability of fasteners is paramount, as any failure can compromise safety, performance, or productivity. This is why standards for fasteners and their protective coatings are so critical: they help ensure strength, corrosion resistance, consistency, and interoperability throughout global supply chains.

With the introduction of CEN ISO/TS 25393:2026, industry professionals gain access to a targeted set of guidelines that specifically addresses electroplating for fasteners—a process essential for enhancing corrosion resistance and controlling surface properties. This article will explore what the new standard covers, its technical requirements, key benefits, compliance considerations, and actionable technical guidance for organizations and professionals alike.

Detailed Standards Coverage

CEN ISO/TS 25393:2026 - Fasteners – Coating System Assessment – Complementary and Additional Aspects to CQI-11

Full Title: Fasteners - Coating system assessment - Complementary and additional aspects to CQI-11 (ISO/TS 25393:2026)

What Does CEN ISO/TS 25393:2026 Cover?

CEN ISO/TS 25393:2026 is a technical specification developed by CEN and ISO to address the unique needs of fastener coating systems. While CQI-11 provides a core framework for coating process assessments in automotive supply chains, it lacks specific guidance regarding fastener applications—this standard fills that gap.

The standard:

• Focuses on electroplating process evaluation for fasteners, emphasizing the expected properties and performance of coatings.
• Addresses areas not fully covered by CQI-11, such as the prevention of hydrogen embrittlement (critical for high-strength steel fasteners).
• Clarifies the application of process audit items and test requirements suited for fastener manufacturing, handling, and procurement.

Key Requirements and Specifications

CEN ISO/TS 25393:2026 draws heavily from other key fastener standards including ISO 4042, ISO/TR 20491, ISO 16047, and ASTM F1941/F1941M. Its main areas of requirements include:

• Electroplated Coating System Evaluation: Specifies process audit items, adapted from CQI-11, that must be assessed, documented, and, where necessary, substituted to consider the unique geometry and function of fasteners.
• Hydrogen Embrittlement Prevention: Outlines documentation, verification, and testing requirements for fasteners susceptible to internal hydrogen embrittlement (IHE), especially those made from martensitic and high-strength steels. Provides tables for correct baking procedures and process checks.
• Coating Thickness and Chemical Composition: Offers guidance (Annex A) on appropriate measurement, documentation, and minimum acceptable values specific to fasteners.
• Mechanical and Functional Fit: Covers gaugeability, assemblability (Annex B), and torque/clamp force testing procedures (Annex C), ensuring fastener performance under service conditions.
• Corrosion Resistance: Details corrosion testing requirements and accepted methods (Annex D), including salt spray and cyclic corrosion protocols.

Who Should Comply and Why?

The standard is applicable to:

• Fastener manufacturers (OEM and Tier suppliers)
• Chemical suppliers providing plating solutions
• Electroplating contractors and finishing facilities
• Purchasers and quality managers specifying or inspecting coated fasteners

Compliance is particularly pertinent in the automotive sector but also extends to aerospace, heavy machinery, and any sector relying on mechanical fasteners with electroplated coatings.

Practical Implications for Implementation

Implementing the specification means re-examining current process audits for:

• Complete process documentation, including adaptations or substitutions of CQI-11 audit items
• In-depth assessment of hydrogen embrittlement risks, especially for high-strength or specialty fasteners
• Recordkeeping for baking processes, plating verification, torque/clamp testing, and corrosion performance data
• Supplier-purchaser agreements regarding unique fastener requirements

Notable Changes and Additions

Compared to CQI-11 alone, CEN ISO/TS 25393:2026:

• Enforces stricter requirements and clearer traceability for hydrogen embrittlement mitigation
• Clarifies ambiguity in existing plating audit questions for fastener-related applications
• Bridges gaps between North American (CQI-11/ASTM) and ISO/European approaches (ISO 4042, ISO 16047)

Key highlights:

• Directly addresses overlooked fastener-specific concerns in CQI-11
• Enhances supply chain confidence for critical coated fasteners
• Simplifies compliance across multiple international markets

Access the full standard:View CEN ISO/TS 25393:2026 on iTeh Standards

Industry Impact & Compliance

How the New Standard Affects Businesses

Professionals across the fastener and broader mechanical component industry should take note: adoption of CEN ISO/TS 25393:2026 is a game-changer for any organization involved in coated fasteners. The standard imposes higher requirements for documentation, testing, and process validation, which can:

• Improve end-product reliability by reducing failures due to suboptimal coatings or overlooked hydrogen embrittlement
• Simplify the qualification of suppliers through standardized assessment and audit checklists
• Facilitate international trade by aligning process requirements with both ISO and CQI frameworks
• Allow organizations to respond promptly to customer and OEM demands for traceability and compliance

Compliance Considerations and Timelines

• Since CEN ISO/TS 25393:2026 is a technical specification valid for a provisional period, businesses should begin adapting QA/QC procedures immediately, especially if trading in European or global markets where fastener performance is a priority.
• Audit schedules should now include reviews of fastener-specific process controls, as outlined in the new standard.
• Supplier and customer agreements (especially regarding unique applications or specialty fasteners) should reference the requirements, especially for hydrogen embrittlement risk and testing.
• Non-compliance may lead to increased warranty claims, rejected shipments, or reputational damage—especially where end-use safety and reliability are at stake.

Benefits of Early Adoption

• Enhanced Quality Assurance: Decreased risk of coating failure, hydrogen embrittlement, or nonconformance.
• Greater Market Access: Easier fulfillment of North American and European OEM expectations.
• Stronger Supplier Relationships: Clear, harmonized expectations across the supply chain.
• Risk Mitigation: Reduced liability from product failures and traceable quality management.

Technical Insights

While CEN ISO/TS 25393:2026 focuses specifically on coated fasteners, it highlights broader technical best practices applicable to all mechanical systems using coated components:

Common Technical Requirements Across Fastener Coating Standards

• Process-Based Audits: Regular, documented self-assessment of all electroplating stages, mirroring a process approach as required by ISO 9001 and IATF 16949:2016
• Baking and Post-Processing: Mandatory documentation and implementation of heat treatment (baking) procedures for high-strength steel fasteners to mitigate hydrogen embrittlement risk
• Verification and Validation: Use of torque/clamp force testing and functional gaugeability checks as part of release and ongoing quality assurance
• Material Traceability: Consistent recording of chemical composition, coating thickness, and treatment details per batch or lot
• Corrosion Resistance Testing: Application of recognized test methods (such as neutral salt spray per ISO 9227) to validate the performance of protective coatings

Implementation Best Practices

1. Gap Analysis: Assess current internal processes against new requirements, particularly focusing on documentation and process controls missing from prior CQI-11-based assessments.
2. Training and Upgrading: Train QA, plating, and inspection staff on the specific requirements outlined in the new standard, including the need for adapted or substituted audit questions and advanced process validation.
3. Supplier Engagement: Collaborate closely with supply chain partners to clarify shared responsibilities for documentation and testing (especially where written agreements for edge cases, such as non-standard fastener geometries or high-hardness washers, are required).
4. Process Control Optimization: Integrate baking and embrittlement control as routine, monitored, and recorded process steps for high-strength and specialty fasteners.
5. Continuous Improvement: Establish regular reviews and updates to internal procedures based on industry feedback, audit findings, and evolving best practices as the standard matures over its provisional application period.

Testing and Certification Considerations

• Baking Records: Maintain accurate logs of baking times, temperatures, and batch IDs for all qualifying fasteners
• IHE Testing Data: Retain results from internal hydrogen embrittlement (IHE) tests, including supplemental testing for high-strength or specialty fasteners as dictated by customer requirements
• Third-Party Audits: Consider engaging external labs or certification bodies for independent review and certification, supporting claims of compliance for customers

Conclusion / Next Steps

The publication of CEN ISO/TS 25393:2026 sets a new benchmark for coated fastener reliability, consistency, and safety in the global mechanical components industry. Its focus on bridging the gaps in self-assessment processes (previously dependent solely on CQI-11) means that manufacturers, suppliers, and customers all benefit from clearly defined, harmonized, and practical requirements.

Key Takeaways:

• The standard specifically addresses coating system assessment for fasteners, closing critical gaps in general-purpose audit checklists
• Enhanced requirements for hydrogen embrittlement prevention and process validation support higher reliability and easier international procurement
• Compliance, though voluntary during the provisional period, positions organizations for success as customer and regulatory scrutiny continues to intensify

Recommendations for organizations:

• Conduct a thorough review of internal and supplier plating processes against the new specification
• Update documentation, training, and testing protocols in light of these detailed, fastener-specific requirements
• Communicate proactively with customers and partners regarding the adoption of the standard to demonstrate quality leadership

Stay updated on future developments and additional guidance by frequently reviewing resources at iTeh Standards, and by engaging with professional organizations and standards bodies as CEN ISO/TS 25393:2026 moves toward potential conversion into a full European Standard.

Access the full CEN ISO/TS 25393:2026 standard and related resources:View CEN ISO/TS 25393:2026 on iTeh Standards