Abstract: A flush pin gauge for checking the position of a center pin in a coaxial connector includes a housing, a fitting on one end of the housing for attaching to a coaxial connector, and a gauge pin slidingly restrained within the housing for engaging the center pin of the coaxial connector. When the gauge is inserted over the conductor spring within the coaxial connector, the gauge pin engages the center pin and causes it to be moved and causes it to be moved longitudinally of the housing. At an opposite end of the housing, there is provided a gauging apparatus which determines from the position of an end of the gauge pin extending through the housing the depth of the pin below the top of the conductor spring. The gauging apparatus comprises a marker which has a width corresponding to the tolerance allowed for the depth of the center pin so that if the end of the gauge pin falls within the marker width, the conductor is acceptable.