AN Fittings

Where? What? How?

AN fittings are a specialised flare fitting which use a specific 37degree mating angle and UNF thread (measured in ‘dash’ sizes) to form a metal to metal seal.

The AN fitting is a particular type of fitting used to connect tubes and hoses for fluid transfer and is a specification derived from the US Military dating back to World War Two stemming from a joint standard agreed upon by the Army and Navy, hence ‘AN’.

The standard agreed upon features a 37 degree mating angle which provides superior sealing in relation to the common 45 degree fittings and also used a much higher thread quality. In time the AN fittings saw widespread military use and in turn numerous manufacturers began producing the fittings, leading to quality issues. An industry organisation called the ‘ Joint Industry Council’ (JIC) sought to standardize the specifications of this fitting thus creating