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.
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’.
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