Kinds of threads

application/pdf Download (796.9 kB)
name profile sign example norm use

metric ISO-thread

  M M20 DIN 13 T1 general

metric-thread

   M30x1 DIN 13 T2

general, if the pitch of the general thread is too large

parallel internal and parallel external thread; a seal is neccessary





 G		 G1/2A DIN ISO 228 T1 (alt DIN259-1) BS2779

external thread for pipes and fittings
G3/4  

internal thread for pipes and fittings

withworth pipe thread; parallel internal thread (with neccessary pipe thread sealant)

  

R		 DIN2999-Rp1/2 DIN 2999 T1 ISO 7/1; BS 21

for pipe-threads and fittings
DIN3858-Rp1/8 DIN 3858

for pipe-fittings

withworth pipe thread; taper external thread (with neccessary pipe thread sealant)

 DIN2999-R1/2 DIN 2999 T1 ISO 7/1; BS 21

for pipe-threads and fittings
DIN3858-R1/8-1 DIN 3858

for pipe-fittings

 

NPT - thread; taper external thread with appropriate jointing medium on the thread

 NPT 1/2-14 NPT male ANSI / ASME B1.20.1-1983

for pipe-threads and fittings

  

NPT - thread; taper internal thread

  1/2-14 NPT female