Published On: April 27, 2021

Molded boots and heat-shrink boots offer rugged, robust connector protection for cable assemblies and related cable harness applications. Either type of boot can provide necessary mechanical protection, insulation, and relief to cables from wear and strain. They can also be cosmetically enhanced for easy identification as much as for aesthetic purposes. Boots are used by numerous industries and businesses of all scales and sizes – aerospace, financial, medical, energy, marine, military, agriculture, automotive, IT, to name a handful – to safeguard the assemblies used to power and operate devices and equipment vital to that sector.

Why Boots are Necessary

Molded heat shrink boots

Boots and jacketing of any kind are, in general, designed to protect cable assemblies from abrasion and wear caused by the elements. The material selection for a boot or jacket must have certain properties for those environments that pose unique challenges which can affect an assembly’s functionality. Common among these are applications used where there is heavy moisture and condensation caused by saltwater or freshwater, or heated, hot, and humid or frigid and cold temperatures extremes.

Other considerations must be accounted for in protecting cable assemblies, too. Many must function under stressful or harsh conditions that require protection from long-term exposure to UV rays, chemicals, acids, or solvents, or they must be able to operate in such places as arid climates, in high altitude, even the upper atmosphere and outer space, and construction and conflict zones. Cable assemblies must also have protection against the effects of oxidation, corrosion, electromagnetic noise, pressure, radiation, and the like.

Choosing Between Heat-Shrink and Molded Boots

Heat-shrink boots and molded boots then, are essential tools used for sealing, protecting, insulating, terminating, identifying, organizing, and providing relief from cable strain. However, as applications and application requirements differ for electronic devices, telecommunications instruments, and electrical components, different boots are used for different purposes. It may be general or specific, but there are different benefits in using molded or heat-shrink boots. Here is why one is typically employed over the other:

Heat-Shrink Boots

Best for:

  • Temperature resistance
  • Moisture resistance
  • Solvents & chemical resistance
  • Applications requiring flexibility

Heat-shrink boots are used in a wide selection of mechanical and electrical applications. They are manufactured to meet design specifications and material property requirements for electrical and electronic interconnecting components and connectors used in cable assemblies. Heat-shrink boots function well in most environments, can seal and safeguard connections, and offer temperature, water, and solvent resistance that is in sync with the application. They are not only designed to ensure functionality under abrasive conditions, but offer excellent protection against mechanical and electrical abuse. Nevertheless, though heat-shrink boots offer exceptional enhanced wire and cable protection for most industrial sectors – agriculture, petrochemical, automotive, medical, etc. – where applications are subjected or exposed to constant or intermittent vibrations, shaking, high impact, and other adverse conditions, molded boots would be the ideal option.

Molded Boots

Best for:

  • Harsh weatherproofing
  • Military applications
  • Tough environmental conditions
  • Heavy vibrations, shaking, or impacts

Molded boots are hard, molded shells designed for high performance applications and manufactured to protect components in the most harsh, hostile, and toughest environmental conditions. More than heat-shrink boots, because of their exceptional weather resistance and ruggedness, molded boots provide the strength and durability necessary for military applications, but also for mass-transit or commercial marine applications. The molded shapes for such applications are considered military grade, that is, the product is designed to meet military specifications that represent an assigned military grade standard and design for a particular piece of equipment, part or component used by the military. No less so than to ensure the integrity of molded boots used to seal cable assemblies and connectors.


Molded boots and heat-shrink boots offer protective solutions for cable assemblies. Boots are effective and reliable tools that protect, organize, and enhance applications. Each boot has different benefits that are dependent on the industry and application requirements of the cable assembly.  In general, molded boots have a more rigid and pre-defined shape designed for use in hostile environments and conditions while regular heat-shrink boots provide the necessary protection required under normal conditions.

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