Hubcap

A hubcap, rim, wheel cover or wheel trim is a decorative disk on an automobile wheel that covers at least a central portion of the wheel, called the hub. An automobile hubcap is used to cover the wheel hub and the wheel fasteners to reduce the accumulation of dirt and moisture. It also has the function of decorating the car.

A "hubcap" is technically the small cover over the center of the wheel, while a "wheel cover" is usually a decorative metal or plastic disk that snaps or bolts onto and covers the entire face of the wheel. Cars with stamped steel wheels often use a full wheel cover that conceals the entire wheel. Cars with alloy wheels or styled steel wheels generally use smaller hubcaps, sometimes called center caps. Alternatively, wheel cover refers to an accessory covering an external rear-mounted spare tire (also known as a spare tire cover) found on some off-road vehicles.

Hubcaps were first used on the Newton Reaction Carriage in 1680. The first hubcaps were more commonly known as dust or grease caps. These caps threaded onto the center hub on the wood, steel, or wire wheel. These were made from the beginning of car manufacturing to 1932. Pre-1915 hubcaps were all mostly made of brass that was nickel-plated. The 1920s hubcaps were mostly aluminum. Grease caps of the wire wheel brands such as Houk, Hayes, Frayer, Dayton, Buffalo, House, Phelps, Pasco, Rudge Whitworth, Budd, and Stewart are some of the hardest to find. When a customer went to buy the wire wheels, the make of the vehicle would be stamped in the center. During 1927 and 1928, the first snap-on center caps were being made on the wire wheels. After 1932, most every car had a snap-on style center cap on the middle of their wire, steel, or wood wheels. Wire wheel center caps in the 1930s had a spring-loaded retention clip system that has been used on many hubcaps and center caps on every style of car and truck to the present day.

Steel wheels in the 1930s had retention clips mounted to the wheel that snapped into a lip in the back of the cap. Wood wheels were a special option. The caps on these had a large chrome base that mushroomed up to another smaller chrome base that would have the emblem on the face. The "stem" up to the second base was usually painted black to make it look as if the top base was floating. These caps were usually made of brass, steel, or aluminum. During the mid-1930s the first full wheel covers were introduced to fit over the entire wheel, except for a small portion of the rim closest to the rubber tire.

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