Carriage Bolts
It has a domed or countersunk head, and the shaft is topped by a short square section under the head. The square section grips into the part being fixed (typically wood), preventing the bolt from turning when the nut is tightened.
Expansion Bolts
Expansion bolts fix into a hole which is similar to the diameter of the bolt. This allows the hole to be drilled through the hole in the item to be fixed. They have double expansion clips that reduce axial and edge spacing and achieve high performance even in cracked concrete.
Elevator Bolts
That’s when you head for the elevator. And that’s when you should say a little thank you to the elevator bolts in the world. The name of these bolts says it all. And without them, you would be spending your time walking up and down stairs instead of comfortably riding between floors.
Shoulder Bolts or Stripper Bolts
Help create a pivot or attachment point. They have a broad smooth shoulder but a small threaded end.
Track Bolt
Track bolts are actually used for railroad tracks. They are also called fang bolts or rail anchor bolts, and they are used to fasten rail joints to link rails or to fix steel rails and rail chairs to railroad ties. These are very strong, high-quality bolts that are specifically resistant to vibrations.
Round Bolt
Round bolts look good, giving a smooth, finished look to projects at the end. They are similar to carriage bolts, but they differentiate themselves by not having the square neck under the head. They are characterized by their smooth round head, and they are tightened by torquing the nut that goes with them. Round bolts are often used in wood connections.
Plow Bolt
Plow bolts are characterized by their flat, countersunk head, square neck, and unified thread pitch. The plow bolt is also similar to the carriage bolt, but the plow bolt differentiates itself with its concave or flathead.
The odd design allows for flush mounting, and sometimes there is also a key that will keep the plow bolt from rotating. Because of this, plow bolts are often used in plows, road graters, bulldozers, and a variety of other pieces of heavy-duty industrial equipment.
Flanged Bolt
Flanged bolts, like many of the other bolts here, have a large head which makes it easier to secure the bolt and identify the object. The circular flange under the head acts as a washer, distributing the load, actually providing about four times the bearing area of a standard hex screw.
Flange bolts are often used in vehicle frames, especially trucks. Flange bolts that aren’t serrated are usually called frame bolts.
