Hexagonal brass bush for insert moulding in plastics (ATSIECM_ATSIECML)

Hexagonal brass insert for overmolding is a metal threaded insert used in injection molding processes to create permanent threaded interfaces within plastic components. It is engineered to prevent both rotational movement and pull-out of the insert during mechanical operation, ensuring long-term structural stability of the threaded connection.

In engineering applications, hexagonal inserts are selected when plastic components must withstand high tightening torque, cyclic loads, vibrations, and repeated assembly operations without loss of thread integrity or mechanical loosening.

The hexagonal geometry is a functional design feature rather than a geometric variant. The flat surfaces of the insert create a direct mechanical interlock with the surrounding polymer material, significantly increasing resistance to rotation compared to cylindrical inserts that rely primarily on surface friction.

How does overmolding work with brass hexagonal inserts?
During the overmolding process, the insert is positioned inside the mold cavity and the molten polymer flows around it, fully encapsulating the external geometry. This creates a structurally bonded metal–plastic assembly in which the insert becomes an integral functional element of the final part, eliminating the need for secondary assembly operations.

What is the functional advantage of overmolding?
Overmolding enables the formation of a permanent metal thread directly inside the plastic component, improving load distribution and eliminating thread wear typically associated with plastic-only threaded systems.

This type of insert is suitable for use with engineering thermoplastics and reinforced polymers, including PA6, PA66, PBT, ABS, and PC, which are commonly used in structural and high-performance industrial applications requiring dimensional stability and mechanical resistance.

The functional principle of the hexagonal design lies in transferring part of the mechanical load from the plastic interface to the insert geometry itself. This improves resistance to both rotational failure and axial extraction under load, especially in applications involving dynamic stress conditions.

Hexagonal brass inserts for overmolding are a standard solution for high-reliability threaded connections in injection-molded plastic components.

They are widely used in applications where long-term mechanical performance must be maintained under vibration, thermal cycling, and repeated assembly cycles, ensuring consistency between manufacturing performance and in-field operation.

ATS technical expertise in supply precision inserts for plastics supports industrial applications where dimensional accuracy, repeatability, and mechanical reliability are critical design requirements.