Abstract: A non powered gripping chuck for closing closures onto a container comprising: a chuck body (16) adapted to be rotated wherein the chuck body (16) is circular and has a circumferential rim, pivoting chuck jaws (22) attached in a spaced apart manner to an annular region proximate the circumferential rim by way of pivot pins (24), where the spaced apart pivoting chuck jaws (22) define a capping zone into which a closure can be introduced. The pivoting chuck jaws have a knurls (32) that are distal to the pivot pin (24), where the knurls (32) come into contact with an introduced closure. Chuck also features biasing means (18) for biasing the chuck jaws against spacing means which maintain a minimum diameter for the closure to be inserted into.