A coating is not decoration. It is a design element with a service life, an environment and a standard. A wrong coating shows up later but always: rust streaks on facade hardware after one season, a seized flange thread, worn protection on a friction unit.
Start from the environment, not the price list
The first question is where and how the product works: a dry heated room, outdoor atmosphere, marine fog, chemical contact, temperature, friction? Each environment maps to its protection class and technology.
A short technology map
Electroplated zinc (6–15 µm) — base protection for indoor and light atmosphere. Cheap and clean-looking; chromating adds durability and colour. Limits: a thin layer and hydrogen embrittlement risk for high-strength fasteners.
Thermodiffusion galvanizing (25–60 µm) — a uniform layer even in threads and holes, excellent in atmosphere and soil, no embrittlement.
Hot-dip galvanizing (40–80 µm) — maximum outdoor life, the standard for steelwork. Needs enlarged thread clearances.
Zinc flake (8–15 µm) — high corrosion resistance without embrittlement and a stable friction coefficient. The choice for high-strength and critical fasteners — automotive, railways, wind power.
Special coatings — zinc-nickel for petrochemicals, nickel and chrome for friction and appearance, anodizing for aluminium, phosphating under paint.
Three questions that save money
What service life is actually needed — a “forever” coating on a part replaced every two years is overpayment. Is there a standard — industry norms often prescribe the coating system directly. How does the coating behave at assembly — the friction coefficient changes the tightening torque, and a thick layer eats the thread tolerance.
The FLOK production loop can organize the application of the full coating spectrum at the specialized plants of the technology network, and our engineers will help choose the system for your environment, standard and batch. Send the drawing, material and operating conditions — we will match the technology and quote the cost.