An assortment of metric tension pins from Hillman. Tension pins are mechanical fasteners that connect and secure two or more parts of a machine relative to each other. They have a body diameter larger than the whole diameter. The spring action of the pin allows it to compress as it assumes the diameter of the drilled hole. The tension pin variants included in this assortment run M1.5 thru M4 in diameter. Full assortments of #45567 contain sixteen (16) refills comprised of Hillman item numbers #45568 - #45583.