Bolts

  • Usually use sizes 8-32, 10-32, and 1/4-20 depending on the application
  • Usually use hex key socket heads since they do not strip as easily as others (add pictures)
  • Use countersunk/flat heads or button heads if there isn’t clearance (space) to have the socket head
  • We use bolts with…
    • Nylock nuts, which have a plastic rim to prevent it from loosening as easily as regular nuts
    • Rivnuts, which can be fit into regular holes when the other side of the bolt is inaccessible

Pros & Cons

  • They are stronger and longer lasting than rivets, but they also add up to a lot of weight. If a mechanism needs to be particularly strong or is expected to take a lot of force (eg. an intake that extends past the bumpers and is prone to hitting against the wall), bolts might be a good choice
  • A chart with hole sizes for regular and tapped (threaded) is available here. Reference it to ensure you make the holes the correct size (usually use close fit).
  • When designing, you need to make sure there is room to fit the appropriate tools to allow for proper maintenance.
    • An allen key (or screwdriver), as well as a wrench (or rivnutter)

Rivets

  • Usually use 3/16” or occasionally 1/4” diameter rivets
  • Can be aluminum or steel depending on the application (add further explanation)

Pros & Cons

  • Are lightweight and easy to replace
  • Can quickly loosen or shear off if they take a lot of force in a weak direction (add pictures)
  • When designing, you need to make sure there is room to fit the appropriate tools to allow for proper maintenance
    • A drill and a riveter