UMA makes a complete line of temperature probes included solid state types. For engine monitoring, we have probes made of brass with thread sized from 1/4-28 to 5/8-18 and various metric sizes, as well as in many different lengths.
Pressure Sensors for Electric Oil, Fuel, Water Gauges. 1/8" npt fitting.
NPT - National Pipe Thread Taper
Note! Pipe thread sizes do not refer to any physical dimensions. The outside diameter of a pipe or fitting must be measured and referenced to a table for size identification.
Note! Inserting a NPT tapered fitting into a port tapped for a straight thread fitting and tightening it can break or severely damage the item the fitting is being installed in.