Sinkittyjä

Sinkittyjä is a Finnish term used to refer to objects that have been tin-coated. Tin coatings are used to protect metal surfaces from corrosion, improve solderability, and create a surface suitable for food-contact or electronics. The coating is typically applied by electroplating or hot-dip tinning, producing a thin tin layer of about 1–20 micrometers. Upon exposure to air, tin forms a protective oxide that helps resist further corrosion, and tin’s relatively low toxicity makes it common for packaging and consumer goods.

Common applications include tinplate, a steel sheet coated with tin used to manufacture food and beverage cans, as well as tin-coated hardware, utensils, and electrical connectors. In electronics, tin finishes on copper or other substrates improve solderability and protect joints from oxidation, although tin whiskers can pose reliability challenges in some high-reliability applications.

Historically, tin coatings date back to the 19th century with hot-dip tinning and later electroplating processes becoming standard. Modern practice often uses lead-free tin finishes, including tin-copper alloys, to meet environmental and safety standards. Tin coatings can be combined with other metals to enhance wear resistance or solderability.

Environmental and safety notes: Tin coatings are generally considered low-toxicity for common consumer uses, but waste management and recycling of tin-coated materials follow standard metal-recovery practices. Tin-coated packaging played a key role in food preservation and continues to be widely used in cans.