RCC-M Special Fasteners – Nuclear-Grade Capability from Energy Bolting
- Dan Pearce
- Jan 9
- 3 min read
Updated: May 16
Energy Bolting are a UK-based manufacturer of high-performance fasteners and precision machined components for the most demanding environments in the energy, defence and nuclear sectors.
Our manufacturing capability extends into Class 1, 2 and 3 fasteners compliant with RCC-M – the internationally recognised design and construction code for nuclear pressure equipment.
RCC-M Fasteners for Nuclear-Class Applications
What is RCC-M? RCC-M is the French nuclear mechanical design code maintained by AFCEN. It governs the manufacture of pressurised components and supports within nuclear plants, including valves, pumps, vessels, heat exchangers, and bolting.
The code defines fastener material, manufacturing, testing, heat treatment and documentation requirements depending on component criticality:
Class 1: Reactor core and primary pressure boundary
Class 2: Safety-critical auxiliary systems
Class 3: Balance of plant (e.g. piping and structural interfaces)
RCC-M also establishes detailed standards for coatings, cleanliness, traceability and packaging – all of which are implemented as standard procedure at Energy Bolting.
RCC-M Compliance at Energy Bolting
We manufacture RCC-M compliant fasteners in accordance with:
RCC-M M5110 – Material specifications for nuclear-class alloys
RCC-M M5120 – Manufacturing rules for fasteners, covering dimensional tolerances, thread accuracy, surface finish and heat treatment control
All fasteners are supplied with full traceability and nuclear-ready documentation:
EN 10204 3.1 or 3.2 certification
Manufacturing records and ITPs
Heat treatment reports for solution annealing and ageing
PMI reports and batch-level traceability
Cleanliness and segregation per RCC-M Section F6000
Where required, coatings align with RCC-M annexes F5200/F5500 – including manganese phosphating and solid-phase diffusion treatments on stainless steels to reduce galling and improve friction properties.
Typical Application & Fastener Configurations
Our RCC-M fasteners are used across multiple reactor systems, including:
Heat exchangers
Piping systems
Turbine casings
Structural penetrations
Mounting assemblies for auxiliary and safety-related equipment
Reactor coolant system (RCS) bolting
Core support structures
High-pressure boundary fasteners
RCC-M compliant fasteners includes threaded studbolts, hex bolts, socket head capscrews and machined nuts – engineered for Class 3 nuclear applications such as piping, structural interfaces, exchanger flanges and auxiliary system mounts.
Engineered bolting for heat exchangers, reactor piping, structural interfaces and auxiliary system mounts.
Product capabilities include:
Studbolts and threaded bars: DIN 2510 Form Z, ISO/UNC/UNF/Whitworth
Hex bolts, socket caps, engineered specials to client drawing
Hex, collar, cap and 12-point nuts
Custom dimensions, threads, and markings
We machine from fully certified European bar stock, compliant with RCC-M M5110 grades:
X6CrNiCu17-04 / 1.4542 / 17-4 PH
Alloy 660 / A286 (1.4980)
Inconel 718 / Inconel 625
Duplex and Super Duplex (1.4410 / 1.4501)
Z5CND17-12, X2CrNiMo17-12-2 and other grades referenced in RCC-M, ISO, and ASTM equivalence tables
Manufacturing Excellence and Quality Control
Batch production of RCC-M compliant fasteners using CNC and thread rolling machinery.
Our Wolverhampton (UK) facility is optimised for batch-based precision manufacturing of nuclear-grade fasteners:
CNC multi-axis turning and milling
Thread rolling and single-point cutting
In-house heat treatment
Centreless grinding and low-contamination marking
Our QA team provides:
ITPs and route cards
Manufacturing Process Plans (MPPs)
Third-party 3.2 inspection if required
Dimensional reports, PMI, MPI, LPI, and UT inspection packs
Clean packaging and segregation prevents contamination during storage, transit, and installation.
Where specified, parts are protected from contamination through:
Separation from carbon steel at all stages
Dedicated packaging per RCC-M cleanliness requirements
Optional VCI type corrosion control sheathing
Why Clients Choose Energy Bolting for Nuclear Fasteners
We combine deep materials expertise, efficient batch production, and full nuclear documentation into a responsive service that’s trusted across the energy sector.
Fastener solutions delivered, manufactured to order - backed by nuclear-specific project documentation.
✓ Fast-turnaround manufacturing of RCC-M fasteners
✓ Expertise in precipitation-hardened and corrosion-resistant alloys
✓ Comprehensive knowledge of RCC-M technical and quality clauses
✓ Clean packaging and segregation built into our process controls
✓ Dedicated account management and export experience
If you’re involved in reactor upgrades, new builds, shutdown maintenance or auxiliary system design – we can help.
Speak to our team about your RCC-M bolting requirements – fast, responsive, and technically assured.
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