RB1238 Reducer Bushing, 1/2 in MNPT x 3/8 in FNPT

Unbranded RB1238 reducer bushing with 1/2 in male NPT and 3/8 in female NPT connections.

A smaller threaded connection

RB1238 is a reducer bushing for joining two different nominal pipe thread sizes. It has a 1/2-inch male NPT end and a 3/8-inch female NPT end. The male end threads into a compatible female port. The female end accepts a compatible 3/8-inch male NPT fitting. Check both sides of the connection before choosing a fitting. A reducer bushing changes the connection size at that point in the line, so it is useful when the existing port and the next fitting do not share the same nominal size.

Check the threads before ordering

Use the printed RB1238 code as a cross-check, then compare the two connection sizes with the equipment or fitting you are working with. NPT identifies the tapered pipe thread series. The size is nominal, so it is not the same as measuring the outside diameter with a ruler. Confirm which side of the assembly needs male threads and which side needs female threads. This listing describes one fitting with a male 1/2-inch NPT connection and a female 3/8-inch NPT connection. It does not identify a particular brand or material.

For sprayer plumbing repairs

A reducer is a small part, but the direction matters. Match the ends to the two parts being connected: this bushing has 1/2-inch male NPT threads and 3/8-inch female NPT threads. The male end has outside threads; the female end has threads inside the opening. Check that both mating parts use NPT and confirm which one has the larger port before ordering. Pipe-thread sizes are nominal, so measuring the outside diameter with a ruler may not identify the size correctly. Use the markings on the existing fittings or check the equipment documentation. This bushing changes the connection from 1/2-inch male to 3/8-inch female at one point in the line. When a connection handles sprayer fluid, check the equipment maker’s specifications for the fitting required for that application.

Product analysis

Verified connection specification: 1/2 in male NPT x 3/8 in female NPT. Primary maker listings associate part code RB1238 with this reducer-bushing specification.

At a glance