Hardware: Fixtures and Fittings (Junior Cert Wood Technology): Revision Notes

Screws

Screws are important in woodworking and assembling tasks. They offer strong holding power and versatility. Unlike nails, screws have threads that provide a secure and adjustable connection.

Types of Screws

1. Wood Screws
   • Features: Tapered body, sharp threads
   • Uses: Joining wood, attaching hardware
   • Benefits: Strong grip, ease of removal
2. Sheet Metal Screws
   • Design: Sharp point, fine threads
   • Usage: For metal-to-metal or metal-to-wood fastening
3. Machine Screws
   • Role: Used in metal assemblies, often with threaded holes
   • Differences: Uniform threads for tapped holes

Parts of a Screw

• Head: Shapes like flat, round, or pan affect screwdriver choice and look.
• Shank: Straight, unthreaded part giving stability.
• Thread: Provides grip by embedding into material; types affect use.

• Example Scenarios:

  Aspect	Screws	Nails
  Application	Adjustable, secure fastening	Quick installation
  Strength	High holding power	Shear and flex strength

  • Screws are better for furniture as they allow changes.
  • Nails are faster for framing or temporary structures.

Selecting the Right Screw

• Materials: Use screws designed for the specific material to prevent splits and keep joints secure.
• Joinery: Right screw length and diameter match material thickness and joinery for best strength.

Using a Screwdriver

• Instructions:
  1. Select a screwdriver that fits the screw head type.
  2. Align the tip with the screw's slot.
  3. Apply gentle pressure and turn clockwise to insert.
  4. Do not over-tighten to prevent damage.
  5. Wear safety glasses to protect from fragments.
• Types of Screwdrivers:
  • Slotted, Phillips, and Pozidriv for different head types.