Choose these metric bolts for fastening most machinery and equipment. They are twice as strong as low-strength steel bolts. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

Good for high-strength fastening, these screws are made from alloy steel comparable in strength to Grade 9 steel. The head makes 12 points of contact with a wrench to handle more torque than a socket head or hex head screw.

About half the strength of medium-strength bolts, these Grade 2 bolts are for light duty fastening. These bolts are commonly used in tight spaces with moving parts, such as grain elevators and other belting systems, because the smooth, low-profile head provides a flush fit when installed. The square neck keeps these bolts from turning when tightening a nut.

Sharp teeth bite into the surface of wood, rubber belting, and other soft materials to keep the bolt from turning when tightening a nut. These bolts are commonly used in tight spaces with moving parts, such as grain elevators and other belting systems, because the smooth, low-profile head provides a flush fit when installed.