The Telemecanique XS4P18NA340 is a current-production M18 threaded inductive proximity sensor in the XS4 series, rated IP68 and delivering an 8 mm sensing distance from a 12-24 VDC supply. Output is NPN normally-open, switching up to 200 mA on a 3-wire prewired cable 2 m long. The nickel-plated PPS body holds up in washdown environments that would degrade standard plastic housings.
Peer cross-check: XS9E11RPBL01M12
Against the block-style XS9E11RPBL01M12 (IP67, PNP NC, 10 mm sensing, M12 connector), the XS4P18NA340 differs in mounting thread, output polarity, and contact configuration. The XS9 travels in a plastic housing with a 4-pin M12 remote connector; the XS4 uses a fixed 2 m cable on a nickel-plated PPS cylinder. Neither is a drop-in for the other without rewiring and adapter hardware.
For BOM freeze or new design, the current-active status means the part is available through standard sourcing without a last-time-buy timeline. Qualification testing should use the 8 mm flush-mount unshielded sensing face as designed.
Installation notes
Threads into a standard M18 tapped hole; IP68 seal requires a clean mating surface. Cable entry is fixed; plan conduit or gland access before pulling. Operates from -13 °F to 158 °F ambient; the PPS body and nickel plating resist mild acids, alkalis, and steam cleaning. Keep the sensing face free of ferrous buildup — 8 mm gap is short enough that debris bridging the face can cause false triggers.