Cast Nylon Sheaves for the Heavy Equipment Industry

In the heavy equipment industry, sheaves play an important role in lifting systems. The grooved wheel components are used alongside ropes, cables, or chains in pulley systems to change both the direction and amount of force employed to facilitate the lifting and lowering of materials and equipment.

Traditionally, sheaves consisted of cast iron or steel. However, the introduction of high-performance plastics and more advanced plastic manufacturing methods have led to the adoption of cast nylon as a suitable construction material alternative. Compared to their cast iron and steel counterparts, cast nylon sheaves offer a number of advantages and find application in a variety of mechanical equipment and systems, such as cranes, forklifts, and wire drawing and cable stranding machines.

Following the acquisition of Timco, Inc. in 2017, the team at W.S. Hampshire is proud to offer customers cast nylon sheaves in various designs and sizes to suit a wide range of heavy equipment applications.

Pulleys vs. Sheaves

Despite the terms “sheave” and “pulley” being used interchangeably, there is a distinct difference between the two parts.

  • “Pulley” refers to the entire mechanical system used to facilitate the lifting and lowering of heavy objects. Their construction includes a wheel and axle or shaft designed to support movement and the directional change of a cable or belt.
  • A “sheave” is a component of a pulley system that assists in the transmission of power by allowing the system operator to change both the direction and amount of force needed for lifting. The use of multiple sheaves increases the mechanical advantage of the pulley system, each one reducing the amount of necessary force by half. Sheaves also minimize friction, helping cable or rope to move freely and reducing wear on the cable.

Benefits of Timco Cast Nylon Sheaves

In comparison to cast iron and steel sheaves, Timco cast nylon sheaves to provide several benefits when used in pulley systems, including: 

  • Lower component weight. Cast nylon sheaves are one-seventh the weight of steel sheaves. In larger lifting equipment and systems, this quality can result in weight savings of up to 2,200 pounds. By reducing the weight of a material handling system, industry professionals can increase operational efficiency, reduce the amount of load and stress experienced, and facilitate handling and operation.
  • Longer service life for wire rope. In material handling systems, the rope or wire cable bears the most stress. The amount of stress experienced by this component from use and external factors directly affects its useful lifetime. The wear resistance and elasticity of Timco cast nylon sheaves reduce the amount of stress relayed to the wire rope, thereby extending its service life by up to 300% compared to their steel counterparts.
  • Improved system safety. Worn or fatigued wire ropes and cables pose the greatest safety risk in material handling operations. Since Timco cast nylon sheaves increase the service lives of these components, the entire system is able to run safely for longer.
  • Greater corrosion and weather resistance. Corrosion significantly affects the amount of friction in material handling systems, resulting in more wear and stress. Cast nylon sheaves are rust, chemical, and saltwater corrosion resistant, making them the ideal solution for lifting systems used in marine and other harsh environments. 
  • Longer pulley system service lives. Cast nylon sheaves can also dampen system vibration, resulting in less wear in other system components such as bearings, shafts, and housings. Less wear means components last longer, resulting in lower maintenance and replacement costs and downtime requirements, all of which translate to more profit.
  • Better durability and longevity. Besides extending the useful life of other system components, cast nylon sheaves also outlast their metallic counterparts.

Quality Cast Nylon Sheaves From W.S. Hampshire

W.S. Hampshire is a full-line custom fabricator and supplier of non-metallic materials, including Timco Technical Plastics and Ryertex Phenolics.  Equipped with years of industry experience and a 135,000-square-foot manufacturing facility, our team has the knowledge and tools to produce standard or custom sheaves to meet virtually any heavy equipment application.

For additional information about our sheaves, contact us or request a quote from one of our experts.

pdf-icon Engineering Plastic Sheaves & Sheave Design


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