Choosing the Right Coating for Outdoor Fasteners
Zinc plating, hot-dip galvanizing, Dacromet or stainless steel? A practical comparison of cost, corrosion resistance and typical applications.
Coating selection is one of the most common questions we receive from distributors, and the right answer depends on exposure conditions, budget and assembly requirements.
Electro-zinc plating is the most economical option, offering 48 to 96 hours of salt-spray resistance. It is ideal for indoor applications and general machinery where appearance matters.
Hot-dip galvanizing provides a thick zinc layer with 500 or more hours of salt-spray resistance, suited to structural steel, solar mounting and outdoor infrastructure. Threads must be oversized to accommodate the coating.
Dacromet and Geomet coatings combine zinc and aluminium flakes in a chromate-free binder, reaching 720 to 1,000 hours without hydrogen embrittlement, which makes them the preferred choice for high-strength automotive fasteners.
Stainless steel A2 and A4 eliminate coating altogether and remain the standard for marine, food and architectural work. Our team can recommend the most cost-effective option for any project.