Spirol has introduced brass reverse expansion inserts for strengthening
plastic joints. The Series 18 fastener has a head and is intended for
applications in which the bolt enters the insert from the headless end,
rather than from the headed end. The head provides a high level of
pull-through resistance and its diamond knurl provides bi-directional
torque resistance for bolt installation. The insert can be cold-pressed
into the plastic hole and no special tools are required.