Overview - ISO 17607-6:2023 (Steel structures - Bolting)
ISO 17607-6:2023 defines the general requirements for structural bolting used in the execution of steel structures and fabricated components. It is part of the ISO 17607 series and is intended to be used together with ISO 17607-1. The standard covers constituent products, hole and surface preparation, assembly, pretensioning and tightening methods, inspection, testing, correction and documentation needed to claim conformity.
Keywords: ISO 17607-6, structural bolting, steel structures, bolted joints, pretensioned bolts, bolt tightening, slip-resistant joints.
Key topics and technical requirements
- Execution specification & quality requirements: Defines responsibilities, execution levels and quality documentation needed before and during erection.
- Constituent products: Requirements for bolts, nuts, washers, direct tension indicators (DTIs), coatings and atmospheric corrosion‑resistant components; verification, identification, packaging and storage.
- Hole and surface preparation: Dimensions and tolerances for boltholes, faying surface preparation for bearing and slip‑resistant joints, and precautions before assembly.
- Assembly and joint types: Joint classification, fit, shims/packing plates, snugging, tightening sequences and use of fit/temporary bolts.
- Pretensioned and non‑pretensioned bolting: Procedures and minimum pretension requirements; pretensioning methods specified in normative annexes - torque method, combined method, spline‑drive twist‑off, direct tension indicator method, and turn‑of‑nut method.
- Tools and calibration: Requirements for pretensioning tools, k‑factor calibration and pre‑installation verification testing.
- Inspection, testing & correction: Inspection stages (pre‑erection, pre‑installation, post‑installation), testing of pretensioned bolts, handling excessive coatings, replacement and reconditioning.
- Annexes & test methods: Normative annexes provide slip factors, nominal pretension tables, calibration and test procedures, and a bolt tightening qualification procedure (BTQP).
Practical applications and who uses this standard
ISO 17607-6 is used by:
- Structural engineers and design offices specifying bolted connections in buildings, bridges and industrial structures
- Fabricators and erectors implementing bolting procedures and quality control
- Contractors, site supervisors and QA/QC inspectors performing assembly and inspection
- Procurement and QA teams specifying and verifying bolting products (DTIs, pretensioned assemblies, coatings)
- Testing laboratories and calibration services for pretensioning tools
Using this standard improves safety, reliability and traceability of bolted joints and supports compliance with project specifications and national regulations.
Related standards
- ISO 17607-1 (general execution requirements for structural steelwork) - to be used in conjunction with ISO 17607-6
- EN 14399 series (referenced for pretensioned bolt calibration in the annexes)
For specification, procurement and on‑site execution of bolted steelwork, ISO 17607-6:2023 is the authoritative reference for consistent, verifiable structural bolting practice.