to severe hoist duty service classification. Serial production hoists were once regarded as being designed for light to moderate hoist duty service classifications, but since the 60's this has changed. Over the years the custom hoist market has decreased in size with the advent of the more durable serial production hoists. A machine shop or fabricating shop will typically use a serial production hoist, while a steel mill or NASA may typically use a custom hoist to meet durability and performance requirements. Overhead hoists require proper installation, operation, inspection, and maintenance. When selecting an overhead hoist, operators must consider the average operating time per day, load spectrum, starts per hour, operating period and equipment life. These parameters determine the Hoist Duty Service Classification, which helps hoist installers and users better understand the hoist's useful life and duty service application. The American Society of Mechanical Engineers also publishes a number or standards related to overhead hoists, including the “ASME B30.16 Standard for Overhead Hoists (Underhung)", which provides additional guidance for the proper design, installation, operation and maintenance of hoists. Construction hoist Also known as a Man-Lift, Buckhoist, temporary elevator, builder hoist, passenger hoist or construction elevator, a construction hoist is commonly used on large scale construction projects, such as high-rise buildings or major hospitals. There are many other uses for the construction elevator. Many other industries use the buckhoist for full-time operations, the purpose being to carry personnel, materials, and equipment quickly between the ground and higher floors, or between floors in the middle of a structure. There are three types: Utility (to move material), personnel (to move personnel), and dual-rated, which can do both. The construction hoist is made up of either one or two cars (cages) which travel vertically along stacked mast tower sections. The mast sections are attached to the structure or building every for added stability. For precisely controlled travel along the mast sections, modern construction hoists use a motorized rack-and-pinion system that climbs the mast sections at various speeds. While hoists have been predominantly produced in Europe and the United States, China is emerging as a manufacturer of hoists to be used in Asia. In the United States and abroad, General Contractors and various other industrial markets rent or lease hoists for a specific projects. Rental or leasing companies provide erection, dismantling, and repair services to their hoists to provide General Contractors with turnkey services. Also,