#4 x 1/8 mpt Adapter Oil Pressure Fitting - Steel

The #4 x 1/8 MPT Adapter Oil Pressure Fitting in steel is a precision hydraulic connector engineered for reliable pressure line applications in performance engines, racing fuel systems, and industrial hydraulic assemblies. This straight adapter serves as a critical bridge between #4 AN (dash-4) male connections and 1/8-inch NPT male ports, eliminating the need for custom fabrication or multiple fittings. Professionals and enthusiasts rely on this fitting wherever direct AN-to-NPT transitions are required—particularly in oil pressure monitoring systems where accuracy and leak-free performance are non-negotiable.

Manufactured by FRAGOLA, a trusted name in fluid transfer solutions, this adapter is constructed from durable steel with a natural finish to resist corrosion in demanding engine bay environments. The 2-inch length provides optimal clearance and installation flexibility, while the straight-thread design eliminates flow restrictions and pressure loss that can compromise gauge accuracy or system response. The #4 AN male end accepts standard -4 hose and fittings, while the 1/8 NPT male thread integrates seamlessly with factory or aftermarket oil pressure ports found on most engine blocks and sensor locations. Steel construction ensures the fitting withstands sustained pressure cycles and thermal cycling without degradation.

This adapter is ideal for builders installing custom oil pressure gauge lines, turbo oil supply/return systems, remote oil filter mounts, and engine management sensor feeds where NPT-to-AN conversion is required. Its compact 0.05 lb weight makes it suitable for weight-critical applications, and the straightforward male-to-male design simplifies installation without requiring secondary adapters. Compatible with any #4 AN hose assembly and standard 1/8-inch NPT threaded ports, this fitting delivers the reliability and precision that serious engine work demands. Proper thread sealant application ensures a permanent, leak-proof connection suitable for full-pressure operation.