Spring washer

• A washer with a split at one point, giving it a helical shape.
• The washer’s shape causes it to exert a spring force between the fastener’s head and the substrate.
• The spring force then creates friction and prevents the fastener from coming loose.

Cup washer

• Used in combination with countersunk screws, such as Cut screws or self-tappers, to obtain a finished look.
• The washer also increases and spreads the grip the fastener applies once it’s screwed in place.

Square washer

• A square washer, as its name indicates, is a large square washer with a round centre hole.
• These washers are specifically designed with heavy-duty fastening in mind.
• The washer’s large size allows it to, evenly and effectively, distribute the load applied by the bolt, underneath the bolt’s head.
• Square washers are more durable than their round counterparts.
• They are mainly used in the building industry as it can withstand stress and vibration better than round washers.
• During the construction of decks, square washers can be used during the construction of the decking structure because it experiences a lot of vibrations, movement and use.
  

Flat washer

• Used to spread the load of a fastener (screw or bolt) when it’s fastened to a substrate.
• Available in sizes small, medium and large.