Threaded Inserts

Unisteel offers a comprehensive range of inserts.

Recommended for use in plastic components, inserts provide long thread life and tight fastening joints. They are designed to improve the strength of assemblies by distributing forces from the screw over a larger diameter of the insert, hence increasing their load bearing capability. They can also be plated for corrosion protection or post assembly processes.


Material : Brass, carbon steel and stainless steel


Installation Type

Molded-in, press-in, self-tapping, ultrasonic and thermal

Installation Type Description


Widely used in thermoset plastics, molded-in inserts are designed to be placed into the mold cavity prior to plastic injection. They provide optimal torque performance and pull-out resistance.


Press-in inserts are ideal for use in softer plastics, where they are pressed into a pilot hole without melting the plastic prior to installation.  They offer quick installation with no specialized equipment and achieve good overall joint performance


Ideal for use in a wider range of plastics including thermoset plastics, self-tapping inserts provide the best pull-out resistance for a post-mold installed part.

Ultrasonic / Thermal

Designed for post-mold installation in thermoplastics, inserts are “welded” into the plastics using ultrasonic vibrations or heat. Ultrasonic/ thermal inserts provide fast, positive anchoring.


Knurl Types

Available in straight, helical and diamond designs, knurls are used to increase resistance to torque.  Various combinations of knurls can be designed on the same insert to achieve an optimum combination of torque and pull-out resistance.

Knurl Type Description


Straight knurl offers the highest torque resistance.


Helical knurl offers a higher axial pull-out resistance than straight knurl, but with a lower resistance to torque.


Diamond knurl offers a high resistance to both tensile pull and rotational torque loads.