一、英制螺纹（螺纹牙型角55度）Thread of British standard ( Thread pitch shapeangle 55)
BSW－－－－英国标准惠氏螺纹（粗牙）BritishStandard Whitworth Thread ( Coarse )
BSF－－－－英国标准惠氏螺纹（细牙）BritishStandard Whitworth Thread ( Fine )
G－－－－直管螺纹（外螺纹分A、B两面级、丝锥分G、G－D）Straightpipe thread ( Outside thread in A\B:taps in G、G－D )
R－－－－锥管外螺纹（旧代号ZG;KG）Outsidepaper pipe thread ( Old thread code ZG,KG )
RC－－－－锥管内螺纹（旧代号ZG;KG）Insidetaper pipe thread ( Old thread code ZG,KG )
二、美制螺纹（螺纹牙型角60度）Threadof American standard ( Thread pitch shape angle 60
UNC－－－－统一制粗牙螺纹（代替NC）Unifiedcoarse pitch thread ( Instead of NC )
UNF－－－－统一制细牙螺纹（代替NF）Unifiedfine pitch thread ( Instead of NF )
UNEF－－－－统一制超细牙螺纹Unifiedsuperfine pitch thread
UN－－－－－统一制不变螺距螺纹Unifiedthread
UNS－－－－统一制特殊螺纹UnifiedSpecial thread
NPT－－－－一般用途锥管螺纹（旧代号Z;K）Taperpipe thread for general purpose ( Old
threadcode Z,K )
NPSC－－－－管接头直管内螺纹Internalstraight pipe thread for connection
NPSM－－－－设备上自由配合，机械连接用直管螺纹Straightpipe thread for general purpose
NPTF－－－－干密封锥管螺纹Drysealtaper pipe thread
NPSF－－－－干密封燃油直管螺纹Drysealstraight pipe internal thread
NGT－－－－气瓶用锥螺纹Specialthread for gas cylinder
三、米制螺纹Metricthread
ZM－－－－－米制锥管螺纹Metric taper pipe thread
四、其它螺纹Other threads
SM－－－－缝纫机螺纹Threadfor sewing machine
PZ－－－－气瓶用锥螺纹Specialthread for gas cylinder
5V1－20V1－气门芯螺纹5V1－20V1－Tyrevalve thread
螺纹代号说明示例：Explanationof thread code. e. g.
1/4－20UNC
1/4－公称直径1/4"nominal dia. 1/4"
20－每寸20牙twentyteeth per inch
UNC－美标统一制粗牙螺纹unifiedcoarse pitch thread ( American standard) |