M6x150mm BZP Cup Square Hex Bolts & Nuts

Also known as coach bolts or carriage bolts.
Extensively used in conjunction with timber tooth connectors for fastening timbers together.
Domed Top and a square under the head, the square section grips into the part being fixed preventing the bolt from turning when the nut is tightened.
DIN603 - Grade 4.6 - BZP.