In this case, the name describes the shape as most banjo fittings have a larger circular section which is connected to a thinner pipe and in a modest way it looks a bit like a banjo. But don’t be confused if you see a banjo bolt and it looks nothing like a banjo, for example, the Norden Hydraulics 300 series double (DBL) banjo bolt just looks like a bolt with some holes drilled into it.
With banjo fittings, fluid can flow up the hollow bolt and then out through the hole and into the spherical shape. From there it flows into the attached pipe. The retaining bolt in a banjo fitting should not be over-torqued or else the union will become distorted.
Banjo fittings and banjo bolts are used in motor cars and other types of vehicles in fuel, oil and other hydraulic systems such as brakes and clutches. They have a perforated bolt which allows fluid to pass and can be connected to either a flexible or rigid (steel) hose.
The main advantage of using a banjo bold is that it withstands high pressures and they can be rotated relative to the fitting avoiding damage to either the hose or fitting when it is screwed into position. The direction of the pipe or hose can also be adjusted before the bolt is tightened.
Banjo bolts are used in fuel lines, as fuel filter connectors, in braking systems at the brake caliper end, in power steering systems and in hydraulic clutch systems.
Since Banjo bolts are used in applications such as brakes or power steering, where failure of the application can result in severe damage to both human life and machinery, it is important to not only select the correct banjo fitting but ensure it is attached correctly.
Norden Hydraulics stocks a wide range of banjo fittings and bolts some are made from 6061-grade aluminium which is anodized others as steel banjo fittings. The range includes 8mm, 10mm, 14.5mm, 12mm, 16mm, 18mm, 3/8”, 7/16” and BSPP (British Standard Pipe Parallel) banjo fittings.
The fittings are for use in oil lines, fuel pumps, fuel filters, carburetors, electronic fuel injection (EFI) systems, braking and clutch systems, and power steering applications.
In steel fittings, there are 8mm, 10mm (3/8”) and 7/16” straight banjo fittings commonly used in brake and clutch connections, as well as a 30 degree, 20 degree and 90 degree fittings in 10mm (3/8”).
Also available in steel are 10mm eye fitting in single or double, 12mm and 14.5 mm eye style, and also a 7/16” fit with or without tail.
Anodised aluminium fittings come in 16mm and 18 mm eye, or 14.5mm double banjo, or as bolts in imperial, metric and BSPP bolts.
If unsure of when or what type of banjo bolt to use contact the experience Norden Hydraulics team.