Abstract: Apparatus and process for applying locking patches of resilient, heat softenable resin to internally threaded articles having openings at both ends, in which the threaded portions of the articles, heated to a temperature above the softening point of the resin to be applied, are moved on a conveyor as a uniform succession at a uniform continuous speed in a path for application of particles of the resin with the openings at the ends of the articles substantially uncovered, a stream of resin particles entrained in a gaseous jet is directed by a resin particle stream guide through the openings in successive moving articles against threaded areas of the articles where the particles adhere and melt to form locking patches, flow of the gaseous jet is controlled relative to movement of a repeating feature of the articles on the conveyor to supply the stream of resin particles when the stream guide is in, and to interrupt the stream of particles when it is out of particle applying relation to the articles, and a sucti