Banjo Fittings

How do you connect an AN hose to a component with a metric thread in a tight space? A banjo fitting routes the fluid through a hollow bolt and a ring-shaped eye, so the hose can run close along the component – for example at a fuel rail or an oil line.

How a banjo fitting works

A banjo fitting consists of an eye with a hose connection and a hollow bolt that threads into the component. The fluid flows through the bore in the bolt and out into the eye. Sealing is typically done with a washer on each side of the eye, and several of Vibrant's aluminium -AN Male Banjo Fittings come with two washers. The low profile makes banjo fittings an obvious choice where a regular AN fitting or a metric adapter would stick out too far.

How to choose the right banjo fitting

Three factors need to match your project:

• Hose size: The AN size must match the hose, e.g. -3AN, -4AN, -6AN or -10AN.
• Bolt thread: Diameter and pitch must match the component, e.g. 10 mm x 1.0 or 10 mm x 1.5 – the two cannot be used in each other's threads.
• Bolt and washers: Check what is included. The Mishimoto M20 x -10AN Black Banjo Fitting comes with a bolt, while other products may require a separate bolt.

Preferably use new sealing washers, as they typically deform when tightened, and tighten according to the manufacturer's instructions – aluminium threads can be damaged by excessive torque. If you need other transitions, you will find more types under fittings and adapters. The category also includes brands such as Radium Engineering, AEM and Forced Performance.

Frequently asked questions

Can I reuse the sealing washers on a banjo fitting?

It is typically not recommended. The washers are compressed when tightened and do not always seal as well afterwards. Use new washers of the correct size whenever a banjo fitting has been removed.

How do I find the right thread for the banjo bolt?

Measure the bolt's diameter and pitch, or check the component's specifications. The same diameter is available with different pitches, e.g. 10 mm x 1.0 and 10 mm x 1.5, so both measurements must match before you order.

Why does my banjo fitting leak after installation?

It can be caused by reused or incorrect washers, dirt or damage on the sealing surfaces, the wrong thread or incorrect tightening. Clean the surfaces, use new washers and tighten according to the manufacturer's instructions.