Reducing Brass Hex Nipple - 1/2in x 3/8in Male NPT - DOT Air Brake Fitting - Eaton 3325X8X6 Parker 216P86 177.9122DC

Bridge the two most common air-line sizes on the truck with this DOT brass reducing hex nipple distributed by FleetPro Parts & Tires. One end is 1/2in NPT male and the other is 3/8in NPT male, which is the step almost every supply-side repair ends up needing: a half-inch reservoir or manifold port feeding a three-eighths valve, coupling or run of line. Do it with a bushing and a separate nipple and you have added a joint, added overhang and given vibration a second place to work a seal loose. Supplied under the Automann brand at Fleet Standard grade, we stock these heavily right here in our Hanover Park, Illinois warehouse to ensure lightning-fast shipping for fleets, diesel repair shops, and owner-operators nationwide.

The Step Every Air System Needs: The DOT 1/2in x 3/8in Nipple Advantage

This fitting meets FMVSS 571.106 / DOT requirements for brake circuits and is built for air brake plumbing on tractors and trailers. Both ends are tapered NPT, so each joint tightens as it is driven and seals on the thread flanks rather than relying on a gasket or an O-ring that ages out. One body, one install, one part to inspect at the next PM.

The brass body copes with condensate, compressor oil carryover and the road salt a heavy-duty air system drags through it, and it will not seize into the cast boss the way plated steel eventually does. At 0.2 lbs the reduction stays compact and close to the port instead of standing off it, and the hex centre lets a wrench torque the nipple on its own. It carries forward the older Automann 177.9514 reference for shops on earlier parts lists.

At FleetPro Parts & Tires, we know this is the reducer that is always missing from the drawer. This Automann nipple is a direct replacement for highly searched industry numbers including Eaton 3325X8X6 and Parker 216P86.

Vehicle Fitment & Compatibility

This universal-application DOT brass fitting is intended for the following commercial use:

• Make/Model: Universal - tractors and trailers
• System: Air brake plumbing on tractors and trailers
• Threads: 1/2in NPT male x 3/8in NPT male
• Compliance: Meets FMVSS 571.106 / DOT requirements for brake circuits
• Component Group: Air Brake & Wheel / Air System Manifolds & Valves

Direct Replacement & Cross-Reference Numbers:

This Automann brass nipple serves as a direct replacement for the following part numbers:

• Eaton Interchange: 3325X8X6
• Parker Interchange: 216P86
• Supersedes Automann: 177.9514
• Automann Distributor #: 177.9122DC

Technical Specifications

• Component Type: Brass Reducing Hex Nipple
• Threads: 1/2in NPT Male x 3/8in NPT Male
• Body Material: Brass
• Application: Air brake plumbing on tractors and trailers
• Compliance: Meets FMVSS 571.106 / DOT requirements for brake circuits
• Replaces Automann #: 177.9514
• Weight: 0.2 lbs
• Package Dims: 1.62 x 1 x 1 in
• UPC: 889626447297
• Product Level: Fleet Standard Aftermarket
• Brand: Automann (Distributed by FleetPro Parts & Tires)