News / Why Fastener Coatings and Finishes Matter for Your Projects

Why Fastener Coatings and Finishes Matter for Your Projects

January 6, 2026

When selecting the right coating option for your project, considerations such as performance, corrosions resistance and cost effectiveness, are key to ensuring long-term performance. Understanding the different types of fastener and fixings coatings will help to make an informed decision that both protects your investment and ensures reliable performance.

Whether you’re working in the marine, automotive, construction or industrial industries, the benefits of various coatings very much matter within a wide variety of projects.

From zinc plating to hot dip galvanising, each coating type offers unique benefits in terms of corrosion protection, wear resistance, temperature tolerance, and environmental durability. The right fastener finish can mean the difference between a project that lasts decades and one that requires costly maintenance or replacement within months.

Our below guide explores 11 of the most popular and effective fastener coating options available. Helping you to understand which solution best meets your specific requirements for bolts, screws, nuts, washers, and a wide range of other fixings.

  1. Black Oxide

A conversion coating that provides a dark attractive finish with minimal dimensional change to the fasteners. This popular coating is created through a chemical process that converts the surface of steel into magnetite, creating a black finish that’s both functional and aesthetically pleasing. Key benefits include:

– attractive black finish ideal for visible bolts and screws

– no dimensional changes to threaded fasteners, ensuring a perfect fit

– excellent for indoor applications and low-moisture environments

– cost-effective finishing solution for high-volume projects

– provides mild corrosion resistance with oil topcoat

– maintains surface smoothness for precision applications

Black oxide coating is commonly used in firearms, automotive components, hand tools, and architectural hardware where appearance matters alongside moderate protection.

  1. Chemical Black

A chemical conversion process that creates a black finish on steel fasteners, offering better corrosion resistance than standard black oxide treatments. This coating penetrates the steel surface, creating a durable bond that resists flaking and peeling. Key benefits include:

– enhanced corrosion protection for fixings in variable conditions

– uniform black appearance across all fastener types

– maintains tight tolerances crucial for precision assemblies

– suitable for precision fasteners in mechanical applications

– better rust resistance than traditional black oxide

– good dimensional stability for threaded components

Chemical black is ideal for machinery, equipment manufacturing, and applications where consistent appearance and reliable protection are required.

  1. Electro Zinc Plating

Available in clear, yellow, and black finishes and is one of the most popular fastener coatings. It offers excellent corrosion protection at an economical price point. This electroplating process deposits a layer of zinc onto steel fasteners, creating a barrier against moisture and corrosion. Key benefits include:

– outstanding corrosion resistance for bolts, screws, and nuts

– multiple finish options: clear (bright), yellow chromate, and black

– cost-effective zinc coating solution for large-scale projects

– Widely available for all fastener types and sizes

– Provides cathodic protection to underlying steel

– Suitable for general construction and manufacturing applications

Electro zinc plating is the go-to choice for general-purpose fasteners, providing reliable protection for indoor and moderate outdoor environments. The different chromate finishes offer varying levels of corrosion resistance, with yellow and black providing enhanced protection.

  1. Iso Fit Galvanise

Iso Fit Galvanise is a specialised galvanising process designed specifically for threaded fasteners, ensuring proper fit and function after coating application. This process accounts for the additional thickness of the zinc coating, preventing thread binding and assembly issues. Key benefits include:

– maintains thread integrity on screws, bolts, and nuts

– superior galvanised corrosion protection for outdoor use

– ensures proper fastener assembly without binding

– ideal for structural applications and steel construction

– meets international standards for galvanised fasteners

– compatible with standard threading gauges and specifications

Iso Fit Galvanise is essential for construction projects, structural steelwork, and any application where galvanised fasteners must assemble easily. All while providing maximum corrosion protection.

  1. Hot Dip Galvanising

The gold standard for corrosion protection, hot dip galvanising immerses fasteners in molten zinc at approximately 450°C, creating a thick, durable coating perfect for outdoor and marine environments. This process creates a metallurgical bond between zinc and steel that provides decades of maintenance-free protection. Key benefits include:

– maximum corrosion protection for fixings in harsh environments

– excellent for outdoor, coastal, and marine applications

– long-lasting zinc coating durability (possibly 50+ years)

– self-healing properties protect fasteners from scratches

– complete coverage including recessed areas and threads

– extremely cost-effective over the product lifecycle

Hot dip galvanising is ideal for infrastructure projects, transmission towers, bridges, outdoor structures, marine applications, and any environment where fasteners face severe corrosion challenges. The thick zinc coating provides unmatched protection against moisture, salt spray, and atmospheric corrosion.

  1. Nickel Coating

A premium finishing solution providing excellent corrosion and wear resistance, commonly used in high-performance and decorative fastener applications. Electroless nickel plating creates a uniform coating with superior hardness and durability. Key benefits include:

– superior corrosion resistance for bolts in chemical environments

– excellent wear protection on frequently assembled fixings

– attractive bright finish for visible applications

– suitable for harsh chemical and industrial environments

– high hardness provides good wear resistance

– non-magnetic properties for specialised applications

Nickel coating is the preferred choice for marine hardware, food processing equipment, chemical processing, and aerospace components. Ideal for any applications requiring both corrosion protection and aesthetic appeal.

  1. Phosphate Coating

A conversion coating that improves paint adhesion, reduces friction, and provides moderate corrosion resistance for fasteners and fixings. This coating creates a crystalline surface that enhances the bond between metal and subsequent coatings. Key benefits include:

– excellent paint adhesion on fasteners for powder coating

– reduces friction for easier assembly and disassembly

– good oil retention properties for lubricated applications

– cost-effective pretreatment coating for painted fasteners

– prevents rust during storage and shipping

– provides a good base layer for enhanced coating systems

Phosphate coating is widely used in automotive manufacturing, painted assemblies, and as a pre-treatment before powder coating or painting. It’s ideal for fasteners that will receive additional finishing or require reduced installation torque.

  1. PTFE / Xylan

PTFE (Polytetrafluoroethylene) and Xylan are high-performance fluoropolymer coatings offering exceptional lubricity, corrosion resistance, and chemical resistance for demanding fastener applications. These coatings combine the non-stick properties of PTFE with resins and additives for enhanced durability. Key benefits include:

– outstanding lubrication reduces installation torque for bolts and screws

– excellent chemical resistance in aggressive environments

– reduces galling and seizing in stainless steel fasteners

– high temperature performance (up to 260°C)

– non-stick properties prevent build-up and contamination

– precise torque control in critical assemblies

PTFE and Xylan coatings are essential for aerospace, chemical processing, pharmaceutical equipment, food processing machinery, and any application where consistent clamping force, chemical resistance, or high temperature performance is required.

  1. Sherardising

A diffusion coating process that bonds zinc to steel fasteners at the molecular level, creating superior corrosion protection without dimensional changes. This process heats fasteners with zinc dust below the melting point of zinc, causing zinc to diffuse into the steel surface. Key benefits include:

– excellent corrosion resistance for fixings in outdoor environments

– no thread damage or dimensional change ensures proper fit

– uniform coating on complex shapes and internal threads

– ideal for threaded fasteners requiring tight tolerances

– no risk of hydrogen embrittlement

– provides barrier and sacrificial protection

Sherardising is particularly valued for high-strength fasteners, springs, small components, and precision threaded parts where maintaining exact dimensions is critical. It’s commonly used in automotive, agricultural equipment, and general engineering applications.

  1. Zinc Flake

Zinc flake coatings, including proprietary systems like Dacromet, Delta, and Geomet, provide exceptional corrosion protection for fasteners in the most demanding environments. Most notably in automotive applications. These coatings use zinc and aluminium flakes in an inorganic binder, creating a coating with superior performance characteristics. Key benefits include:

– superior corrosion protection exceeding 1000 hours salt spray

– high salt spray resistance for coastal and winter road conditions

– no hydrogen embrittlement risk for high-strength bolts

– excellent for automotive fasteners and chassis components

– thin coating maintains thread tolerances

– outstanding performance-to-weight ratio

Zinc flake coatings have become the industry standard for automotive underbody fasteners, brake components, suspension hardware, and any application requiring maximum corrosion protection with minimal thickness. These coatings are essential where road salt, marine environments, or extreme weather conditions can challenge the fastener integrity.

  1. Zinc Nickel

A premium alloy coating combining zinc (typically 85-90%) and nickel (10-15%), offering outstanding corrosion protection that exceeds standard zinc plating by up to 10 times. This electroplated coating provides the sacrificial protection of zinc with the enhanced durability of nickel. Key benefits include:

– exceptional corrosion protection for fixings (500+ hours salt spray)

– superior to standard zinc plating in harsh environments

– excellent for automotive applications and brake systems

– high temperature resistance up to 200°C

– no chromate required for enhanced environmental compliance

– ideal for critical safety fasteners

Zinc nickel plating is increasingly specified for automotive fasteners, particularly brake assemblies, powertrain components, and safety-critical applications. It’s also used in aerospace, defence, and industrial applications where extended corrosion protection is essential.

Choosing the Right Fastener Coating for Your Application

Selecting the appropriate coating for your bolts, screws, nuts, and fixings depends on several factors. Such as, environmental exposure, corrosion requirements, budget constraints, and aesthetic preferences.

Choosing the right coating for your fasteners and fixings is critical for project success, performance, and longevity.

Our experienced team can help you select the optimal coating solution based on your specific requirements, environmental conditions, and performance expectations.