Specifications of International Thread Standards
AbbreviationCountryThread Angle
°
Description
ISO60°International Organization for Standardization
UNUSA60°Unified National 8-, 12- and 16 pitch series
UNCUSA60°Unified National Coarse
UNEFUSA60°Unified National Extra Fine
UNFUSA60°Unified National Fine
UNJUSA60°Unified National thread series with
external thread controlled root radius
UNJCUSA60°Unified National Coarse thread series
with external thread controlled root radius
UNJEFUSA60°Unified National Extra Fine thread series
with external thread controlled root radius
UNJFUSA60°Unified National Fine thread series
with external thread controlled root radius
UNJSUSA60°Unified National Special thread series
with external thread controlled root radius
UNRUSA60°Unified National thread series
with external thread controlled root radius
UNRCUSA60°Unified National Coarse thread series
with external thread controlled root radius
UNREFUSA60°Unified National Extra Fine thread series
with external thread controlled root radius
UNRFUSA60°Unified National Fine thread series
with external thread controlled root radius
UNRSUSA60°Unified National Special thread series
with external thread controlled root radius
UNSUSA60°Unified National Special
NPTUSA60°National Pipe Taper 1:16
NPTFUSA60°National Pipe Taper Fuel and Oil
Dryseal 1:16
NPTRUSA60°National Pipe Taper Railing Fittings
NPSCUSA60°National Pipe Straight Coupling
NPSFUSA60°National Pipe Straight Fuel
NPSGUSA60°National Pipe Straight Grease
NPSHUSA60°National Pipe Straight Hose
NPSIUSA60°National Pipe Straight Intermediate
NPSLUSA60°National Pipe Straight Loose
NPSMUSA60°National Pipe Straight Mechanical
BSWGB55°British Standard Withworth Coarse
BSFGB55°British Standard Fine
BSPPGB55°British Strandard Pipe Parallel
BSPTGB55°British Standard Pipe Taper
BAGB47°British Standard Association
NCUSA60°National Coarse,
replaced with UNC in 1948
NFUSA60°National Fine,
replaced with UNF in 1948