tech&des- screws and nails

• Wood Screws


  An effective way of joining materials together
• Counter sunk head screws


  • Used when the screw head had to be flush with the surface of the work
• Round head screws


  • Can be used when the head does not need to be flush
• Nails


  The quickest way to join pieces of wood, can be used alone or with glue, have a straight shank and no threads, and are hammered into wood
• Nail punch


  • Used to drive the head of the nail below the surface, has a hollow end to grip the nail head
• Nails are quicker to use than screws


  But the joint is not as strong
• Nuts and Bolts


  Used to join pieces together either permanently or temporarily
• Bolts used in structures

  • The Eiffel Tower in Paris was originally a temporary structure and after twenty years it was to be dismantled
• Coach bolt


  • Has a square collar under the domed head that locks into the wood when the nut is tightened, a washer is normally placed before the nut to stop it sinking into the wood
• Countersunk machine screw


  • Fits level with the surface of the wood/metal/plastic, a screwdriver is used to keep the bolt still while the nut is tightened
• Plain washer


  • Prevents the nut sinking into the surface of the wood/plastic/metal, a spring washer is used if there is a need to prevent a nut and bolt loosening
• Self-tapping screws


  Have hardened threads that cut their own threaded holes in hard plastic and thin metals
• Semi-permanent joining methods
• Screw come with different types of slots
• Nail Punch is a semi-permanent joining method
• Bolts are used to join pieces together either permanently or temporarily
• Two spanners are needed to tighten a machine bolt and nut