Description

Overview

The 1/4 x 3/8 NPT male connector connects 1/4-inch outside-diameter nylon air-brake tubing to a 3/8 NPTF female threaded port. Its straight brass body provides a compact transition from smaller imperial air lines to larger threaded connections on compatible pneumatic equipment.

Features

• Push-in collet accepts 1/4-inch OD nylon air-brake tubing.
• 3/8 NPTF tapered male pipe thread.
• Integrated tube support and gripping mechanism eliminate the need for a separate compression nut or olive.
• Brass hexagonal body provides a tightening surface, while the release collet permits tube removal during servicing.

Specifications and Materials

The connector combines a brass body, internal tube support, gripping collet and pneumatic sealing components. The straight passage joins the two connections without an additional adaptor. Its male pipe thread uses a tapered sealing arrangement rather than the O-ring face seal found on parallel metric connectors.

Part number: DQ68DOT0406.

See the manufacturer DOT imperial male connector specifications

Compatibility and Fitment

The 1/4 x 3/8 NPT male connector requires 1/4-inch OD (6.35mm) imperial nylon tubing and a compatible 3/8 NPTF female port. The tube and thread measurements describe different connection types. Check both separately before replacing the fitting.

Do not substitute 6mm metric tubing or connect the tapered thread to BSP or straight metric ports. Confirm the existing threaded connection’s sealing requirements before installation.

These cross-references show where this part replaces the part numbers and applications listed. Some installations may need minor changes. 35-680406, 35680406, AQ68-DOT-4X6, AQ68DOT4X6, 1868X4X6, 3115 56 18DOT, 31155618DOT, 68PTC-4-6, 68PTC46, PL1368-4C, PL13684C, S68PMT-4-6, S68PMT46, 95453018M

Related Parts

Compare these connector sizes and configurations when the existing tube, port or installation angle differs.

Compliance and Safety

The DOT push-in fitting range is designed for compatible heavy vehicle pneumatic systems. Depressurise the circuit before installation. Cut the nylon tube squarely, remove damaged ends and push fully into the collet. Use the appropriate NPTF sealing method, tighten through the brass hex and avoid overtightening the tapered connection. Restore pressure and leak-test both ends.

Trailer Applications

This connector suits compatible trailer brake-control valves, pneumatic manifolds, air-suspension controls and auxiliary air equipment where a 1/4-inch nylon line terminates at a 3/8-inch female pipe port. Its straight configuration suits installations with direct tube entry.

Cross-reference and Suitability

This part cross-references to or suits the following equivalent part numbers and compatible alternatives:

Why Choose ICS Trailers

ICS Trailers supplies imperial nylon air fittings for truck and trailer pneumatic repairs. If an existing connector is unmarked, send the tube outside diameter, thread measurements and a photograph of the fitting so we can help identify the correct replacement.

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