Secondary Processes and Finishes in Wire & Spring Manufacture

At William Hughes, we provide a variety of secondary processes and finishes designed to boost performance, durability, and aesthetics of springs and wire components. We pride ourselves on being specialists in surface treatments throughout the UK and Europe, where all surface finishing processes are delivered within a quality-controlled environment and underpinned by ISO 9001 and IATF 16949 certifications. Each treatment is carefully matched to the end-user application, mechanical load profile and customer specification, meeting the highest standards of durability, performance, and regulatory compliance.

Our advanced capabilities include the use of the latest technology including Fanuc robots and our fully automated electrophoretic paint production line. We can also offer KTL Black, plastic coating, threading, pointing, nibbing, clip application, Delta®-Tone finishing, Delta®-Seal, steel and glass shot peening, injection overmoulding and various welding techniques. We understand these processes are integral to meeting industry standards and by completing all component finishes within our own manufacturing facilities ensures this is not compromised.​ In offering these services in-house we ensure consistency, reduced lead times, and strict quality alignment across every component we deliver. Our capabilities are designed to meet the high standards of the aerospace, medical, and advanced industrial sectors.

Customising Wire Form Surfaces

Our in-house specialists work closely with design engineers and procurement leads to select, apply, and verify the most appropriate finishing processes. These include advanced and multi-layer anti-corrosion techniques. Each process is engineered to heighten the mechanical, chemical, or thermal characteristics of wire forms and springs used in high-spec applications.

The solutions that our secondary processes offer include:​

Increased Corrosion Resistance

Through processes like electrophoretic painting and Delta®-Tone finishing, components gain superior protection against environmental factors.​

Improved Mechanical Properties

Techniques such as shot peening and nibbing enhance fatigue strength and durability

Aesthetic and Functional Finishes

Our wire painting and plastic coating services offer both visual appeal and functional benefits, such as noise reduction and insulation.​


Our Range of Finishes and Secondary Processes

William Hughes offers a range of secondary processes and finishes, each tailored to specific application needs:​

Electrophoretic Painting (E-Coating)

Electrophoretic painting, also known as e-coating or cataphoretic painting, involves immersing components in a water-based solution containing paint particles, followed by the application of an electric current to deposit a uniform coating. Applied via our fully automated electrophoretic paint production line or e-coating line, this process provides corrosion resistance and consistent film thickness.

  • Ideal for: Automotive suspension wires, aerospace brackets, HVAC components
  • Advantages: Uniform coating thickness ( approx. 20–22 microns), excellent corrosion resistance (up to 800 hours salt spray), an environmentally friendly process and RoHS-compliant finish

Plastic Coating

Wire forms can be overcoated or sleeved with thermoplastics or elastomers to provide insulation, damping, or resistance to abrasion and chemicals. This process is especially valuable in the medical, electronics, and automotive sectors. Our plastic coating includes Nylon PA11 or PA12, offering both protective and functional benefits.​

  • Ideal for: Automotive interior components, applications requiring noise reduction and electrical insulation.
  • Advantages: Insulation effect, corrosion resistance, easy identification.

Threading, Pointing, and Nibbing

Where mechanical assembly or fastening is required, we can customise end features of the wire form through threaded ends, conical points, or reduced diameters (nibbing) for insertion into mating parts. These mechanical processes are essential for preparing wire components for assembly and ensuring secure connections.​

  • Ideal for: Components requiring precise end formations for assembly.​
  • Advantages: Improved assembly efficiency, enhanced mechanical interlocking.​

Clip Application

We also offer integrated clip or fastener applications, enabling ready-to-install wire components. Crimping techniques can be used to secure composite assemblies or prepare parts for overmoulding. Our clip application services involve attaching clips to wire components, facilitating easy assembly and integration into larger systems.​

  • Ideal for: Automotive cable systems, aerospace routing components
  • Advantages: Reduces assembly time and increases component integrity

Delta®-Tone Finishing

Delta®-Tone is an inorganic zinc flake coating providing superior corrosion protection without the risk of hydrogen embrittlement, while Delta®-Seal provides an organic top coat that enhances resistance to chemicals and mechanical wear. We apply the Delta-MKS® suite of finishes for customers requiring high-performance anti-corrosion protection without compromising dimensional tolerances.

  • Ideal for: Fasteners, clips, and wire forms used in aggressive or corrosive environments
  • Advantages: High corrosion resistance, thin and flexible coating, available in various colours for component identification

Colour Coding: Can be used for colour coding, we do Red, Blue, Green, Black, Silver & White.

Injection Overmoulding

For highly specialised applications, wire forms can be partially or fully overmoulded with precision polymers, creating hybrid components that combine the strength of metal with the flexibility or insulation of plastic.

  • Ideal for: Electrical carriers, medical assemblies, modular systems​
  • Advantages: Integrated functionality, reduced part count, enhanced user safety

Welding Techniques

We offer various welding techniques, including MIG, MAG, TIG and spot welding, to assemble wire components securely.​

  • Ideal for: Structural assemblies in automotive and aerospace applications.​
  • Advantages: Strong joints, consistent quality, efficient production.​


Leaders in Robotics for Welding Wire Forms

At William Hughes, our approach to welding is grounded in precision, repeatability, and continuous innovation. Welding wire forms, particularly for safety-critical or load-bearing applications, requires not only technical capability but also a deep understanding of metallurgical behaviours, joint fatigue, and manufacturing integration. Our UK and Bulgaria facilities house dedicated welding development areas with multiple Fanuc robots and high-resolution scanning equipment, enabling rapid, repeatable welds with tolerances to within fractions of a millimetre. Our processes are continually refined in collaboration with OEMs and Tier 1 suppliers to meet emerging design and compliance challenges.

Our automation programme includes rigorous testing of weld fatigue life, heat-affected zone analysis, and automation integration to improve consistency and throughput. With in-house expertise in MIG, MAG, TIG, and resistance welding, we’re able to deliver robust joints with precise control over penetration depth, distortion, and surface finish quality—essential when welding fine-gauge or formed wire structures.

This facility now serves as both a production centre and an innovation platform, allowing us to trial welds on new wire geometries, test different filler materials, and fine-tune parameters for customer-specific solutions. Our work in this space reinforces our commitment to excellence in wire form manufacture and to delivering future-ready, engineered assemblies for the most demanding sectors.

Robotic Welding Case Study for Automotive Seat Frames

In response to increasing demand from the automotive sector for precision-welded seat components, William Hughes recently invested £1.4 million into state-of-the-art robotic welding technology at our UK headquarters. This investment was driven by a requirement to manufacture welded seat frames for a leading automotive brand. The application demanded not only geometric consistency across thousands of units but also resistance to high cyclic loading in real-world use. By automating the weld path with the use of multiple Fanuc robots and incorporating real-time joint scanning, we reduced rework rates by 40% and improved production cycle times, all while maintaining full traceability and adherence to IATF 16949 standards.

Advanced Finishing and Secondary Process Facilities

Our Plovdiv, Bulgaria factory features advanced electrophoretic painting lines, Delta®-Tone and Delta®-Seal application systems, and comprehensive welding stations. The Electrophoretic Paint Line (E-coat/KTL) is a fully automated facility engineered for the high-volume, high-precision coating of complex wire forms and metal components. This system delivers uniform, corrosion-resistant finishes even in recessed or intricate geometries, making it ideal for components used in demanding environments such as automotive underbodies and medical housings.

Each secondary process is conducted under tightly controlled environmental conditions to ensure consistent results and minimal contamination. We are also committed to sustainable manufacturing practices, employing closed-loop filtration, water recycling systems, and low-VOC coatings wherever possible. These measures not only reduce our environmental footprint but also ensure compliance with REACH, RoHS, and automotive OEM sustainability standards – reinforcing William Hughes’ position as a trusted partner for manufacturers.

Quality and Inspection Techniques

Our commitment to quality is underscored by certifications such as ISO 9001 and IATF 16949, reflecting our dedication to continuous improvement and customer satisfaction.​

Our quality assurance protocols include:​

  • Visual and Microscopic Inspections: trained inspectors assess components for uniformity, coverage, and the absence of defects such as blisters, pinholes, or discolouration.
  • Coating Thickness Measurements: Using non-destructive methods like magnetic induction, we measure coating thickness to ensure compliance with specified tolerances.
  • Salt Spray Testing: Salt spray (fog) testing, in accordance with ASTM B117, assesses the protective quality of finishes against corrosive environments.
  • Adhesion Tests: Confirming coating durability.​

FAQs

Q1 What is the typical coating thickness achieved through electrophoretic painting?

Electrophoretic painting typically achieves a uniform coating thickness of 20–22 microns, with the capability to increase up to 40 microns if required.

Q2 How does Delta®-Tone finishing protect components?

Delta®-Tone provides a zinc-rich, inorganic coating that offers superior corrosion resistance without the risk of hydrogen embrittlement, making it ideal for springs and wire components.

Q3 Can plastic coatings affect the functionality of springs?

While plastic coatings like Nylon PA11 or PA12 offer cushioning and corrosion resistance, their thickness and hydroscopic nature can influence spring performance and should be considered during design.

Q4 What are the benefits of injection overmoulding?

Injection overmoulding enhances component durability, provides insulation, and allows for the integration of additional functional and ergonomic features, streamlining assembly processes

Q5 Can William Hughes apply finishes to components not manufactured in-house?

Yes, we offer finishing services for externally manufactured components, provided they meet our processing criteria.

Q6 Are your secondary processes environmentally friendly?

Yes, our processes, such as electrophoretic painting, use closed-loop systems that minimise waste and environmental impact.

Q7 Can you provide colour-coded wire finishes for component identification?

Absolutely. Our Delta®-Tone and Delta®-Seal finishes are available in various colours, facilitating easy component identification and aesthetic requirements.

Q8 What industries benefit from your secondary processes?

Our services cater to automotive, aerospace, medical, and other precision-driven industries requiring high-quality, reliable components.​

Q9 Do you offer custom secondary processing solutions?

Yes, we tailor our secondary processes to meet specific client requirements, ensuring optimal performance and integration into their products.​

Q10 Can you provide documentation for traceability and compliance?

Certainly, we supply comprehensive documentation, including certificates of conformity and process records, upon request.