Understanding Strain Relief: Essential Protection for Cables and Hoses

Strain Relief
Strain Relief

Strain relief is an important mechanical protection device to protect cables and hoses from a variety of mechanical loads. When connecting flexible cables to end pieces, for example, plugs, fittings, or cable outlets then this protection is essential. Strain relief protects the cable from tensile, pressure, turning, or bending stresses, and resistance to these vibrations means a longer life span for your cable – with less latency in connections.

How It Works

One such strain relief mechanism will secure the cable in a conduit or connector. It absorbs external forces so that they do not reach the internal contacts in a connector or cable inside a control cabinet. This feature is vital for applications that require a long-lasting connection and the integrity of sensitive electronics.

Why Cables Need It

Cables are mechanically stressed by pulling, bending or continuous movement. The forces can extend the cable over the outside arm and, conversely, shrink it at intervals if located on an internal bend point, stretching or pulling it out of housings, connectors or cable glands. This kind of stress can, over time, kink or even physically abuse the conductor.

Strain relief in static electronic systems is used as protection for the cables to ensure they cannot move from their original location. It will hold constants in the structure so repairs can proceed without risk of disconnection or a loss of completeness.

Types and Designs

There are many types and shapes of strain relief devices, each type specifically designed for a specific application. There are also dome-style or flex-style types of brackets, and the latter will refer to rigidity.


The dome-type strain relief ensures a high degree of protection and rigidity, avoiding cuts to the cable from sharp edges at connection points.
They are usually made of aluminium, brass (UV resistant), nylon, steel or stainless steel and other plastics.


Flexible strain reliefs that protect the cable from crimping damage. A wide range of other materials are available which are also well suited to more flexible applications such as robotics.

Common Designs

  1. Metal Strain Relief – Most metal strain reliefs are springs, they protect from high bend stress and cuts. Frequently used materials are steel, aluminium, stainless steel or brass.
  2. Plastic Strain Relief: Plastic strain reliefs are becoming more popular also and can be designed from nylons, polyesters, PTFE or PVC. They can be:
    • One-Direction: only bends in one direction.
    • Multi-DirectionJunior (Movement in various ways, suitable for a wide range of applications)
    • Solid is strong enough to protect and easy to clean, making it a great choice for food/beverage/medical industries.

Other Types

  • Wire Ties: for easily and conveniently bundling wires together.
  • Cable Bushings: Protect cables from chafing where they enter or exit.
  • Romex Connectors: for non-metallic sheathed cable electrical work.

Design Considerations

To be considered when designing strain reliefs, several factors must be taken into account:

  1. Size: The strain relief must be the same size as your hardware products, which count wire ties, cable glands and bushings.
  2. Materials: The material you use affects the effectiveness of this strain relief and its suitability for different applications.
    • Aluminium + Brass: light, anti-corrosion.
    • Flexible, rugged and electrical insulating: PVC, TPR and Nylon….
    • Steel and Stainless Steel: Of great resistance to mechanical stress and aggressive environment.

Formal and Production Requirements

Top 5 Requirements of Strain Reliefs in Consumer Products Their use can be directly moulded as plugs or designed as slide-on components. 3D-printed prototypes enable testing and refinement before production.

Applications and Industries

Regardless of the industry, strain relief forms an integral part of mechanical and plant engineering as well as the food sector. Any locations where cables are strained should have sufficient strain relief. But the kind of strain relief matters only concerning where you use it and what its purpose is.


Strain reliefs are essential to prevent cables from bending at severe angles, sharp corners or experiencing mechanical stresses. With the right design and materials for your needs, these devices can contribute to a great extend to a better lifetime and performance than electrical cables or other flexible products.