Hot-dip and electroplated galvanizing are two common galvanizing processes; they differ greatly in zinc thickness, rust-free years, and appearance. Wrong environment choice leads to white and red rust quickly. The names are similar, but real performance differs several-fold; buyers must distinguish them.
Hot-dip galvanizing immerses the workpiece in molten zinc at about 450°C, with a zinc layer usually 65~120μm thick, forming a zinc-iron alloy layer and providing 10+ years of rust protection; suitable for outdoor, humid, and chemical workshops. The downside is a rougher surface with zinc spatter, and high temperature can distort precision cages—sizes need extra clearance.
Electroplated galvanizing deposits a zinc layer in a plating bath, only 8~20μm thick, bright and even in appearance, suitable for dry indoor environments; rust protection is usually 1~3 years, and humid or acid-alkaline conditions quickly bring white rust, with red rust inevitable outdoors long-term.
In cost, hot-dip is about 1.5~2.5 times electroplating, but is more cost-effective over the rust-protection years. Identification is simple: use a thickness gauge to measure zinc—30μm and above is basically hot-dip; look at the surface—silver-gray rough with spangle is hot-dip, bright mirror is electroplated. Coastal high-salt areas must use hot-dip.
Selection advice: outdoor, coastal, and humid workshops choose hot-dip; dry indoor and cost-sensitive choose electroplated. Nanjing Tongnuo Warehouse Equipment Manufacturing Co., Ltd. offers both processes and recommends by operating conditions and required service life.