Chain
A chain is a unit of length traditionally used in land surveying. The most common version is the Gunter’s chain, which equals 66 feet or 22 yards, approximately 20.1168 meters.
The chain was introduced by English clergyman Edmund Gunter in the 17th century to simplify land measurement. One chain consists of 100 links, each 0.66 feet long. It became a standard unit in British and American land surveying and was instrumental in defining land areas, especially in the U.S. Public Land Survey System.
Key Conversions:
1 chain = 66 feet
1 chain = 22 yards
1 chain ≈ 20.1168 meters
10 chains = 1 furlong
80 chains = 1 mile
Though now largely replaced by metric units and modern surveying tools, the chain still appears in older land deeds, maps, and rural property descriptions.
Centiinch
A centiinch is a very small unit of length equal to one-hundredth of an inch (0.01 inch). It is not commonly used in everyday measurement but may appear in fields requiring precise fractional measurements based on the inch.
Key details:
1 centiinch = 0.01 inch
Equivalent to 0.254 millimeters
Used for fine measurements where inch subdivisions are preferred
Rare and mostly of specialized or historical interest
The centiinch allows for more detailed measurements within the inch system, similar to how centimeters subdivide a meter.