1/2" NPT To 3/8" Barb Straight Barb Hose Fittings (Oil Cooler)

These 1/2″ NPT to 3/8″ barbed hose fittings are designed for use in external oil systems where a 1/2″ threaded port needs to be adapted down to a 3/8″ oil hose. Commonly used on external oil coolers, these fittings are ideal when running smaller diameter oil lines while still utilising standard 1/2″ NPT cooler ports.

Each fitting features a 1/2″ NPT tapered thread, allowing it to screw directly into the inlet and outlet ports on most external oil coolers, remote filter heads, or thermostats. The tapered thread design ensures a tight and reliable seal when installed with suitable thread sealant. On the hose side, the 3/8″ barb provides a secure grip for oil hose, ensuring a strong connection that resists leaks and hose slippage under pressure.

These fittings are particularly useful in custom oil system setups where space is limited or where a 3/8″ hose system is already in place. In a typical full flow oil system, oil exits the engine, passes through external lines to the oil cooler via these fittings, and then returns to the engine. By stepping down to a 3/8″ hose, these fittings allow flexibility in system design while maintaining reliable oil circulation.

For installation, you may also require 3/8″ oil hose, hose clamps, and thread sealant. These fittings are often used in combination with other NPT adaptors depending on your oil system layout.

Sold as a pair, these fittings provide both inlet and outlet connections for your oil cooler setup.

Vehicle Fitment

Aircooled VW:

• Beetle (1949–1979) – All engines
• Beetle Cabriolet (1949–1979)
• T2 Split Bus (1950–1967)
• T2 Bay Window (1968–1979)
• T25 / T3 Aircooled (1979–1983)
• Karmann Ghia (1955–1974)
• Type 3 (1961–1973)
• Trekker (1968–1983)
• Buggy / Baja (Type 1 based, 1949–1979)

Watercooled VW:

• T25 / T3 Watercooled (1983–1992) – when fitted with custom external oil cooling systems

Key Features

• 1/2″ NPT male thread (tapered for secure sealing)
• 3/8″ hose barb for smaller diameter oil lines
• Ideal for external oil cooler inlet and outlet ports
• Perfect for custom or space-restricted oil system setups
• Suitable for full flow oil systems
• Durable, leak-resistant design
• Supplied as a pair (2 fittings)