Pipe Die for 3/8" Black Pipe

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hey guys, im in the process of building a pressure blaster, its pretty well done, i just need to thread the pipe, i have a tap and die set but it only goes up to 1/2". anyone know what size die i need to put threads on?
Reply:ok is the 3/8" outside dia or inside dia???   when I hear 3/8"pipe I am thinking it has a 3/8" dia ID. If so you need a 3?8" pipe thread die.  whatever size the pipe you have you need a pipe thread die.  this is very different from a regular die.  a pipe thread cuts a tapered thread as pipe threads are tapered so they seal.Also fyi a hex shaped die with no split is for rethreading threads.   to cut new threads you use a die that has a split in it.never never never cut threads dry.  lots of oil
Reply:thats the inside dia.. i've threaded alot of stuff with this little kit i have, always works  good. if i measure the outside dia would that give me the size i need? i was hoping somone knew so i don't pick up the wrong one
Reply:If you are threading the outside you want a threader with a 3/8" NPT die like this usually. There's a special die handle thats used to turn the dies.http://www.northerntool.com/webapp/w...3574_200243574Inside threads you'll need a 3/8" NPT tap.Most plumbing supply's will have both. Depot or Lowes may have the dies, but near me they've stopped carrying most of that stuff. HF has cheap sets usually. Taps might be a bit more difficult. 1/4" NPT isn't hard to find, but the larger sizes usually require going to a supply house or industrial supply.As said you need lots of oil, and if doing it by hand usually its best to stop every so often and back up the tap or die to clear the threads..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:if you are threading 3/8" pipe you need a 3/8" npt die. Pipe od is the same no matter what the wall thickness is. 3/8" od is 0.675, you will need at least sch. 40 pipe to put threads onto, it you get less it will just peel the starter thread off .G3miller... 225g, s32p, 250x, 304, 12vs, MSW41     victor o/a thermal dynamics cutmaster 50 lenco panel spotter        hobart hf-boxG3 Farms.....raising cattle, hay, kids and hell, ...oh yeah I'm a fire sprinkler contractor by trade.
Reply:i didnt realize the die's were so different. im looking on ebay for a set, getting everything shipped to Canada sucks .Thanks for the help
Reply:Originally Posted by KYZAAChey guys, im in the process of building a pressure blaster, its pretty well done. . .
Reply:I just go to the local plumbing supply house and buy it already threaded on the end and long enough to do what I need to do on the other end. They sell it pre-threaded in varying lengths.Bill LambertArgon WeldingABQ NMSic gorgiamus allos subjectatos nunc
Reply:Originally Posted by denrepPlease do tell. And how much PSI should the 3/8 pipe be expecting? Good Luck
Reply:Originally Posted by denrepPlease do tell. And how much PSI should the 3/8 pipe be expecting? Good Luck
Reply:Originally Posted by ArgonWeldingI just go to the local plumbing supply house and buy it already threaded on the end and long enough to do what I need to do on the other end. They sell it pre-threaded in varying lengths.
Reply:Originally Posted by DSWHome Depot / Lowes will custom thread pipe usually to length at no charge. For a job I did last year, it was cheaper for me to buy a 10' length of pipe and have then cut and thread it rather than buy prethreaded lengths..
Reply:remember when you thread pipe you effectively reduce the thickness to about 1/2 of what was there.the thread is a weak spot.if finding the dies etc is a pain in the asss just buy nipples cut em in half and weld em on......
Reply:Originally Posted by weldbeadremember when you thread pipe you effectively reduce the thickness to about 1/2 of what was there.the thread is a weak spot.if finding the dies etc is a pain in the asss just buy nipples cut em in half and weld em on......
Reply:Originally Posted by Pro-FabThis is a bad idea. Unless you are certified for pressure welding, do not weld any air line. You can use mechanical fittings (threaded) on pipe under 2" up to 150 psi., and even then, if there was ever an accident, you must be able to prove that the system was built to code, because ABSA will be all over you. The npt threads are tapered, so as long as you don't run the die any farther than is necessary for full contact, weakness won't be a problem.This type of work goes on every day without incident, but you must be aware that the liability is there.