BASE AND BRACKET
ASSEMBLY
1) KING PIN - The essential ingredient. Can be nut and bolt, riveted or stacked.
2) TOP PLATE - Sometimes referred to as the base plate. Usually has four mounting holes.
3) TOP CUP AND RACEWAY - With double ball bearing swivels, the upper raceway carries the load, and the wider the better.
4) BRACKET - May be stamped, cast, welded, drop forged, etc. Referred to as the yoke, rig, horn, etc.
5) LUBRICATION - A fitting may be provided for greasing the raceways.
6) LOWER CUP AND RACEWAY - The lower raceway allows for more ball contact, absorbs side thrust, and affords better swiveling action.
7) KING PIN NUT - Can be tightened for closer tolerances.

WHEEL
8) SIZE AND TREAD WIDTH - For example, a 6 x 2 wheel is 6" diameter, with a 2" tread width or wheel face.
9) LUBRICATION, HUB - A fitting is sometimes located in the hub for anti-friction bearings.
10) WHEEL BEARING - Can be Plain, Delrin, Oilite, Anti-friction: Roller, Ball or Timken.
11) SPANNER BUSHING - Round, cylindrical. Spans between the bracket legs, within the bearing and over the axle, allowing the wheel to rotate.

12) LUBRICATION, AXLE - If desired, lubrication can be applied through the axle, through the spanner and into the anti-friction bearing.
AXLE ASSEMBLY
13)¥ Nut and bolt axles can be replaced. Shouldered types do not necessarily require a spanner.

AXLE / BEARING ASSEMBLY ILLUSTRATIONS

STRAIGHT AXLE FOR FLANGE BALL BEARINGS - No spanner necessary. Zerk through hub or axle.

SHOULDERED WITH PLAIN, DELRIN OR OILITE BEARINGS - Shouldered part provides its own spanner.

SHOULDERED WITH ROLLER BEARINGS - Spanner is virtually always used. Zerk through axle.

SHOULDERED FOR BUTT BALL BEARINGS - Has self-contained spanner. Grease through axle only.

STRAIGHT AXLE WITH ROLLER BEARINGS - Spanner used. Zerk through hub or axle.

STRAIGHT AXLE WITH TIMKEN BEARINGS - Bearing rides directly on axle. Zerk through hub only.