How is a screw built?

Basic Slotted Countersink Steel Wood or Machine Screw.

  • step one: A coil of round wire is put on a machine called a HEADING machine, in this case a 2 stage cold heading machine which is fed through the machine and straightens the wire then cut off at the desired length of the screw plus the amount of material it needs to form the head, on the first stage it is transferred to the centre of the die and punched in with its first tool called a former which creates the shank and the first shape for of the head, then its second stage forges the head shape with a tool called a punch, in this case it would be flat and the die would be countersunk, or if pozi drive is required the punch would look like the end of a pozidrive screwdriver and forges the shape, this produces a blank screw no thread just head and shank.
  • step two: The blank would be taken to a second machine called a Slotting machine, this machine clamps the blanks to a dial and then moves around the dial passing a saw + coolant, the saw then cuts a slot in the centre of the head for the flat screwdriver tool.
  • step three: the slotted blanks are then taken to a third machine called a thread rolling machine, where they are conveyed down a rail and rolled between two flat plates at the desired width and thread which are also called thread rolling dies which use a spinning action to cut the thread.

There are lots of other screw types and different processes, this is just a basic screw.

Please ask for any other methods wanted.