What is S Gauge or S Scale?
S scale (or S gauge) is a model railroad scale modeled at 1:64 scale, S scale track gauge (space between the rails) is 0.883 in (22.43 mm). S gauge trains are manufactured in both DC and AC powered varieties. S gauge is not to be confused with toy train standard gauge, a large-scale standard for toy trains in the early part of the 20th century.
The term "S Scale" was adopted by the National Model Railroading Association (NMRA) in 1943 to represent that Scale that was half of 1 gauge which was built to 1:32 scale. A.C. Gilbert's improvements in 1:64 modeling and promotions of S gauge largely shaped the world of 1:64 modeling today.