SPIROL’s Series 28 Long Headed Inserts are designed for straight holes with a 1° maximum (included) draft angle and are typically installed with heat or ultrasonic vibration. The Series 28 Long Inserts are similar to the Series 27 Long Inserts with the addition of a head for increased bearing area. The Series 28 Long Headed Inserts have the same body style as the standard Series 30 Long Headed Inserts with a reduced center knurl diameter for plastic assemblies where the boss diameter is less than 2x the body diameter of the Insert. The Series 28 also comes in a Short version to reduce costs and installation time for applications requiring less demanding torque and/or pull-out resistance. The SPIROL’s Series 28 Headed Inserts are available to order in inch threads ranging in size from 2-56 up to 5/16-18.