Splined Threaded Insert

A splined threaded insert is a metal fastener that provides strong threads in soft or thin materials. It has splines on its outer body that press into a hole and resist turning. It usually comes in low profile or large flange forms.

A splined threaded insert presses into a drilled or moulded hole in a panel or casting. The splines bite into the base material to stop the insert turning. It takes a machine screw or bolt of the matching thread and is set with a press or insertion tool.

This kind of insert is often made in steel or stainless steel. Steel gives high strength and can be plated for corrosion resistance. Stainless steel suits outdoor or wet areas.

This is a general guide to checking this kind of part. It says nothing about any supplier's parts.

Ask for a certificate of conformance and a mill test certificate if the material grade matters. On receipt, check the thread form, spline condition and that the insert sits flush. Confirm the hole size and that the insert does not spin after setting.