You would be nuts to try to ride a skateboard without the nuts and bolts.
Horrible puns aside, this category is where all of the hardware, washers, kingpins, and nuts will be.
When choosing your hardware size, it is a good idea to keep in mind if you are running risers and how thick your board is. On most 7 ply skateboards, you will only need about 1" hardware, while on a 9 ply longboard with 1/2" risers, you will be needing 2"+ bolts to mount the trucks on the board. The Truss head hardware is what we put on longboards and most cruisers, as it does not sink into the wood and will not sacrifice the integrity of your board over time. With skateboards on the other hand, you want the flat heads so that you do not feel the bolts under your feet as you will be standing on top on them at some point.
For bushing washers, you will want a large cup washer for barrel bushings and a small cup for cone bushings. Don't be afraid to flip the washers on the road side for a less restrictive feeling ride.
The average kingpin size on most reverse kingpin trucks is about 2.75" long. On traditional kingpin trucks, they feature a hammer in kingpin which will actually need to be hammered in or out to be replaced.