Centalic PQ50-B-5.5GG Test Probe, Needle Tip, 50mil

The Centalic PQ50-B-5.5GG is an ICT spring probe on 1.27 mm (50 mil) minimum centres — the fine-pitch end of Centalic's PQ range, for boards whose test points are packed too tightly for 75 or 100 mil (2.54 mm) probes. It works with a matching PQ50 receptacle pressed into the probe plate, so a worn probe is pulled and replaced without touching the plate or the wiring.

The B tip is a needle: a single sharp point that puts the whole spring force onto a very small area, so it breaks through flux residue and light oxide and lands precisely on a small pad. That precision is exactly why you want it at 50 mil (1.27 mm) pitch, where a wider crown head would overhang neighbouring features. It will mark the target — for cosmetically sensitive or plated surfaces choose the cupped A tip instead. The 5.5GG suffix denotes the 150 gf (5.5 oz) spring, the firmest of the three PQ50 options and the one to specify when contact reliability on contaminated boards matters more than board load.

• Needle (B) tip, gold-plated
• 1.27 mm (50 mil) minimum centres; mounting hole ø1.0 mm
• Rated stroke 4.30 mm, full stroke 6.35 mm
• Spring force 150 gf (5.5 oz) at rated stroke
• 3 A continuous, contact resistance 60 mΩ max
• BeCu plunger, Au/Ni plated; phosphor-bronze barrel and casing, gold-plated; gold-plated spring
• Sold per unit; requires a matching PQ50 receptacle