7.8 Riveting Mind Map

7.8 Riveting Mind Map

1. Rivets

   • Formed head
     • Protruding or countersunk
   • Hole drilled through parts
     • Tail end hammered
       • Cross-sectional area increased

2. Sizes

   • 3/32in
   • 1/8in
   • 5/32in
   • 3/16in

3. Material

   • Most common: Aluminium alloy
   • Steel
   • Titanium

4. Heat Treatment

   • Softens rivet to prevent cracking
   • 2017 (D) & 2024 (DD) Rivets
   • Process
     • Two phases
       • Solution treatment
         • Heating
         • Soaking
           • Starts when minimum soaking temp reached
         • Adequate temperature
       • Quenching
         • Insertion into water to cool
         • Transfer time no longer than 15 seconds
   • Refrigeration
     • Delay natural aging process
     • No longer than 5 minutes after quenching: 2024
     • 30 minutes after quenching: 2017
     • 7 day: -18 degrees celcius
     • 20 days: -20 degrees celcius

5. Joints, Spacing & Pitch

   • Pitch
     • Centre of one fastener to centre of another
   • Edge Margin
     • Centre of fastener to nearest edge
   • Spacing
     • Distance between fastener rows
   • Sphere of influence
     • Area of sheet which rivet will achieve water-tight joint
   • Allowance
     • Amount of protrusion of the rivet shank sufficient to form tail
   • Inter-rivet buckling
     • Pressureised fuselage
       • Maximum permissible spacing: 6D or 18t
     • Wing structure
       • Maximum rivet spacing: 3.75D or 4.5D for Hi-lok

6. Dimpling

   • Coin dimpling
     • Sharply defined hole edges
     • Top and bottom of dimple formed to 100 degree angle
       • Can be nested
   • Radius dimpling
     • Lower side angle greater than 100 degrees
       • Cannot be nested
     • Equipment smaller
       • Can be used in areas too tight for coin dimpling
   • Hot dimpling
     • Used on Magnesium or harder Aluminium alloys
     • Material heated
       • Prevent cracking
       • Amount of heat carefully controlled
         • Excess can destroy temper condition