The axis around which steered wheels pivot; a bolt that holds the axis in place—a kingbolt
The pin at the centre of the triangle of bowling pins (originally the tallest pin in kayles). Sometimes also the headpin at the apex
An especially machined stub shaft which extends vertically from the lower surface of an upper coupler assembly and which locks into a fifth wheel
A rivet, or threaded stud or bolt with nut, that holds the mounting plate and horn assembly of a swivel caster together Forged as an integral part of mounting plate on higher quality casters for maximum rigidity and strength
The joint which connects the spindle to the frame The positioning of the kingpin in the frame affects caster and camber This position is adjustable in some frames For a discussion of these terms, see this wonderful document on Pete Muller's karting website
Large bolt that holds the components of the trucks together, in the centre, with a large nut on the end closest to the ground when riding Known to break or snap unexpectedly, causing injury or death
On a tadpole, the bearing or bushing which is the steering pivot for the front wheels
If you describe someone as the kingpin of an organization, you mean that they are the most important person involved in it. one of the alleged kingpins of Colombia's largest drugs ring. = linchpin
{i} one who is very important and influential (i.e. in a company) {Slang}; main part, essential element {Slang}; front pin {Bowling}; vertical pin in a knuckle joint, steering joint in a motor vehicle
Strictly speaking, the 5-pin, because its action is usually the key to knocking down more pins; occasionally used to refer to the 1-pin