QA Tech 125-SDN250S, 23A, Solder Cup

The QA Technology 125-SDN250S is a socket from the 125-25 series — 0.125 in (3.18 mm) centres, 0.250 in (6.35 mm) full stroke — which QA designs for loaded-board and high-current testing. It is pressed into the fixture's probe plate and the spring probe seats in it, so probes are exchanged during maintenance without touching the wiring.

This is the standard-material solder-cup build of the series: an N tube (nickel silver, no finish) with an S solder-cup termination. Choose it for general 125-mil work; step up to the gold-plated G tube, or to the high-conductivity H tube of the 125-SDH250S, where contact resistance on a high-current channel matters more than cost.

• QA 125-25 series: 0.125 in (3.18 mm) centres, 0.250 in (6.35 mm) full stroke
• Tube N — nickel silver, no finish
• Termination S — solder cup
• Mounting hole 0.0940 – 0.0960 in (2.390 – 2.440 mm) in AT7000/G10/FR4; drill 2.4 mm or #41
• Studio records a 2.4 mm mounting hole, 2.5 mm press-fit hole and 7.62 mm collar height
• Paired in Studio with the QA 125-PRG2509S, 125-PRH2509S and 125-PRG2541S probes