KNARR Launches Next-Gen Ejector Pins with Helical Venting Geometry.

KNARR has introduced the next generation of ejector pins for mould cavity venting — a solution that tackles a classic problem in injection moulding: air and gases trapped in the closed cavity, which compromise part quality. Instead of the traditional ground flat surfaces on ejector pins, which often lead to burr formation and accelerated wear, the company developed a high-precision helical geometry with a channel depth of 0.02 mm maintained over the entire length of the ejector pin. This ensures reliable venting, improved guidance of the ejector within the fitting bore, and significantly reduced wear compared to conventional solutions.

The ejector pins are available in all standard diameters from 2 to 12 mm, including intermediate sizes, in lengths up to 450 mm (up to 750 mm for special versions). In addition to the hardened standard version (part no. 300133), KNARR also offers a variant with DLC coating (300133DLC), which requires no additional lubrication and helps prevent clogging of the helical grooves.

The latest addition to the lineup is a solution for smaller diameters, from 0.5 to 4 mm, developed following successful internal testing and strong customer feedback. For these sizes, the helical channel depth is reduced to 0.01 mm, and the ejector pins are manufactured from HSS (high-speed steel) for added stability — available with DLC coating (300533DLC) or without (300533), in lengths from 100 to 315 mm.