This is a 3/8in x 1/4in taper union, male-to-male (M x M), designed to join two female tapered pipe threads of differing nominal sizes in compressed air and pneumatic systems. Its primary use is as a reducer union where a 3/8in BSPT port must be adapted to a 1/4in BSPT port while retaining a pressure-tight tapered thread joint.

The fitting is machined from brass (commonly CW614N) with a nickel plate finish to give improved surface hardness and additional protection against corrosion in workshop environments. The threads are tapered pipe threads conforming to ISO 7-1 / BS 21 (BSPT), with both ends supplied as male tapered threads. As a passive fitting there is no head or drive type; assembly is by hand-tightening followed by a controlled spanner finish and sealing with PTFE tape or a thread sealant appropriate to BSPT joints.

Typical applications include compressed air distribution, pneumatic tool hookups, air line manifolds, plant maintenance and repair, and general industrial reductions where differing thread sizes must be joined without introducing a swivel coupler. The product is commonly used in automotive workshops, manufacturing plants, light engineering, agriculture and HVAC service where reliable tapered-thread seals are required.

Key benefits of this taper union are its inherent corrosion resistance due to the brass substrate and nickel plate, good dimensional stability under repeated assembly and disassembly, and compatibility with standard BSPT threaded components and accessories. The tapered thread form creates a pressure-tight joint when correctly assembled, and the brass material offers good machinability and resistance to dezincification in normal service conditions.

This item forms part of the Draper Tools Group D range and is available from Duchy Fasteners in the stated 3/8in x 1/4in M x M configuration. We hold common sizes and thread reducers in stock and supply them singly or in trade packs to suit workshop and site requirements. If you need alternative sizes or bulk quantities please contact Duchy Fasteners for availability.