Self Tapping & Drilling Screws

Self Tapping Screws - BDN Fasteners

What is a self tapping & drilling screws?

Self tapping screws can drill its own hole while being driven into the material. Available in a wide range of tip and thread patterns, these come in various head designs. The screw thread covers the entire length of the screw from tip to head. Unlike softer substrates, self tapping/drilling in harder substrates is created by a gap in the continuity of the screw thread. All these screws do not come in a sharp or pointed tip. The screws with blunt tips are used mostly for packaging.

Classifications of self tapping screws:

There are essentially three classes –

  1. Thread forming- These self tapping screw displace the material next to the pilot hole and are generally used in materials in which that require more internal pressure to enhance resistance.
  2. Thread cutting- This class of screws has cutting edges and hollows that dislocates the material to create a mating thread. The torque is kept to a low level because of the cutting action. Thread cutting screws are used in the material where too much internal pressure is not required.
  3. Thread rolling- Mostly used on any thick gauge metal like steel, brass, zinc, and aluminum, the thread rolling screws are the best alternative to thread-forming screws. They require high driving torques for installation.

Commonly used Self tapping screws:

 self tapping screws

  • Countersunk or flat head screws- This kind of screws are produced by self drilling screw manufacturers for a flat finish and a smooth outcome since the head of the screw gets fixed below the surface of the material.
  • Allen or socket head screws- When you drive an allen or socket head self tapping screw into the material, the head remains intact and does not get distorted.
  • Bulge head screws- Available in a flat or countersunk head with a concave bearing face, the pressure of a bulging head self tapping screw is distributed over a wider area in comparison to a flat head screw.
  • Flange head screws- If you need to attach plastic to plastic or metal to metal, this is the right option for you as this kind of screws allow more clamping torque as compared to other types of head.
  • Hex head or socket screws- This kind of screws come with a hexagonal head and is used for heavy-duty applications where there is no requirement of a countersunk head.
  • Water head screws- With a flat top surface and countersunk bed, these screws fit perfectly on wood and other soft material.
  • Pan head screws- The head of these screws are round and the sides are vertical. High torque applications are known to use this category of screws.
  • Pancake head screws- For a large clamping area, pancake head self tapping screws are ideal.
  • Button head or dome head screws- These are dome-shaped and are required in carpentry. The dome shape of the screw prevents the head from sinking into the surface of the material becomes less.
  • Truss head screws- Suitable for material with large diameter holes, the screw heads in truss head self tapping screws are wide and have a slightly rounded surface.

Major Difference between the self drilling screw and self tapping screw:

  • Self drilling screw- These are designed specifically by self drilling screw manufacturers to fasten thin pieces of metal together. The self drilling metal screws are used both as a drill as well as a fastener. These screws are available with an additional feature of a drill point.
  • Self tapping Screw- This kind of screws can efficiently in tap their own thread. In order to secure these screws perfectly into the material, you need to drill a pilot hole. As you drive the screw in, the threads will penetrate into the material. Ideally, a self tapping screw is used for soft materials such as wood, metal or brick.