Probe Tube Finishes

Probe tubes may be clad, plated, or left unplated, depending on the intended application.

The following is a summary of the various options and their applications:

“N” STYLE PROBE TUBE

This nickel silver tube with no cladding or plating is suitable for most bare board test applications where probe resistance below one ohm is acceptable, or when lower cost is desired. Oxides which form on the inside surface of the tube can impede current flow between the tube and plunger.

“G” STYLE PROBE TUBE

The “G” tube is a nickel silver tube with a layer of gold plating on the outside surface of the tube. On larger center probes, the plating also covers the inside of the probe tube and improves performance considerably compared to the “N” tube.

“P” STYLE PROBE TUBE

The “P” tube is deep-drawn from nickel silver alloy with precious metal clad on the inside surface, and is used for in-circuit testing where low and consistent electrical resistance is necessary. The deep-drawing process hardens the gold, improving wear characteristics and results in a gold layer of extremely uniform thickness along the entire inside surface of the tube.

“H” STYLE PROBE TUBE

The “H” tube is made from a proprietary, high conductivity alloy, gold plated. These tubes are used in high current applications, very humid environments, or where extremely low electrical resistance is required.

“S” STYLE PROBE TUBE

The “S” tube is made from a proprietary, high conductivity alloy, silver plated. These tubes are used in high current applications or where a lower cost is desired.

Tube Materials Marking Color
N Nickel Silver; No Finish Red
G Nickel Silver; Gold Plated Red
P Nickel Silver; ID Precious Metal Clad Blue
H High Conductivity Alloy; Gold Plated Black
S High Conductivity Alloy; Silver Plated N/A