JIS B1180 specifies metric hex bolts commonly used in Japanese automotive, machinery, equipment, and industrial applications. These bolts are often selected when replacing original hardware on Japanese equipment where thread pitch, head size, and fit must match the original fastener.

Unlike many DIN / ISO hex bolts, JIS B1180 bolts may use smaller across-the-flats head dimensions and different thread pitch patterns depending on diameter. This makes proper identification important when replacing hardware in maintenance and repair applications.

JIS B1180 defines:

• Metric hex head bolts and screws

• Thread pitch by diameter

• Hex head dimensions

• Across-the-flats wrench size

• Mechanical strength requirements

• Manufacturing tolerances

These bolts are commonly used where Japanese metric hardware specifications are required. Always verify diameter, pitch, length, strength class, and head size before substituting DIN / ISO hardware.