A 60 mm pressure pin with a 3 mm tip on a 6 mm base, used to hold a PCB down against the counter-force of the probe field during in-circuit test. It mounts in the fixture's hold-down plate and bears on a clear, component-free area of the board, keeping the DUT seated so probe travel and contact force stay repeatable across cycles.
Pressure pins are selected by length to suit the gap between the hold-down plate and the board surface in a given fixture stack-up. The 3 mm tip is a general-purpose size, broad enough to spread hold-down load without demanding a large component keep-out, and the 6 mm base is common to the whole length range, so pins can be swapped by length without reworking the hold-down plate.
