is a Japanese Industrial Standard that specifies requirements for hexalobular socket head cap screws (commonly known as Torx®-type socket head screws). The standard covers dimensions, mechanical properties, and technical delivery conditions.
: The head diameter and height are typically 5% to 20% smaller than a standard pan head to accommodate tighter spaces. Materials : Steel : Often Class 4.8 carbon steel with zinc plating. jis b 1188 pdf