A solid strain relief is easier to clean which can be an important consideration for many medical applications. Strain reliefs can be solid and smooth or segmented. When the strain relief is over molded, the clamp is embedded into the mold material which greatly increases the tensile strength of the assembly. The strength of the union of the strain relief to the connector can be improved further by providing features that will allow the strain relief to physically bond to the connector body.įlat surfaces show cable clamp that has been crimped onto the cable jacket increasing tensile strength when captured in overmoldĪdditional tensile strength can be achieved by incorporating a clamp which is crimped onto the cable jacket prior to molding. Tensile strength will be increased if the strain relief chemically bonds to both the cable jacket and connector body. A well designed strain relief should isolate electrical terminations, preventing force from being applied to these points.ĭesign considerations for a strain relief include the geometry of the part, the interaction of the strain relief and cable jacket material. The point where the cable or wire is terminated is generally considered the most likely point of failure in terms of flex life and tensile strength. Typically raw cable or wire will withstand a higher number of flex cycles and have a higher tensile strength than a cable assembly. In most instances, a custom designed and over molded strain relief offers superior flex life, tensile strength, and moisture protection performance than a pre-manufactured strain relief.įlex Life and Tensile Strength PerformanceĪ well designed strain relief can enhance both flex life performance and tensile strength. Most off-the-shelf connectors have corresponding pre-manufactured strain reliefs available to fit a variety of cable diameters and are often available in different colors. After the cable conductors are terminated to the connector, the strain relief is screwed or glued onto the connector assembly. Pre-manufactured strain reliefs are typically slipped over the cable before the connector is terminated. A custom strain relief can be designed as a separate unit to be slipped onto cable or can be designed to be molded over cable, commonly capturing a portion of the connector.Ī custom strain relief pre-molded and designed Strain reliefs can be either pre-manufactured or custom designed and manufactured for a specific application. Pre-manufactured and Custom Strain Reliefs If it is likely that the cable will be flexed, it is common to use a combination grommet and strain relief for through-hole applications. Cables that pass through an opening into a device typically employ a grommet to anchor the cable to the device and provide protection against damage from an axially applied load. An effective strain relief should prevent any load applied to the cable from being transferred to conductor terminations.Ī grommet, with an integrated strain relief, is commonly used when a cable is permanently attached to a device. A properly designed strain relief will prevent mechanical force applied to the exterior of a cable from being transferred to the electrical terminations within the connector or device which could lead to failure. A strain relief, also commonly called a bend relief, is important to the electrical and mechanical integrity and overall performance of a medical cable assembly.Ī strain relief is used to provide a transition from flexible cable to a rigid connector or connection point.