Abstract: A spring for each end of a tubular carrier to secure them against sliding and slipping within the tube. The spring having a tongue carrying on its tip an upwardly jutting pin which is upwardly resilient. The pin latches into through apertures in the top wall of the carrier and may have a camming means forward of the pin comprising a pair of ramps extending forward and down from the pin and symmetrical about a longitudinal axis.The tongue has a base and in one embodiment extends rearward of the base. In a preferred embodiment the tongue has a base and extends forward of the base. The tongue may have a surround, and in the preferred embodiment the tongue may extend forward of a lower ledge at the rear of the surround.In use, as the spring enters the carrier against a chip, the pin is cammed down. When the spring is compressed against the chip sufficiently, the pin enters an aperture in the top wall of the carrier, and latches the spring.