Final answer:
The minimum amount of bearing required for the ends of joists, beams, or girders is 1.5 inches.
Step-by-step explanation:
The ends of each joist, beam, or girder must have not less than 1.5 inches of bearing on wood or metal.
Most ball bearings are made of a type of steel known as high carbon chromium steel, often called chrome steel. This is used for reasons of cost and durability. Bearings are also made from other materials such as stainless steel, ceramics and plastic.
Wood bearings are made from lubricant-filled maple wood to make it self-lubricating. Wood bearings absorb debris and are ideal for corrosive and abrasive applications where grit, fine contaminants and moisture are present.
The most commonly used bearings are Deep-Groove Ball Bearings. Thanks to their simple design, they are easy to maintain and not as sensitive to operating conditions thus are used in a wide range of different applicaitons. In addition to radial forces, they absorb axial forces in both directions.