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G Thread? 3

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Buckets

Mechanical
Dec 16, 2003
3
I have a block with a G1/4 thread in it. One person tells me this is a British standard thread. Another tells me it is a American standard. Could someone tell me what this G thread is so that I can get the correct fittings.

Thanks
 
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Thanks everyone for your responses. I now have the correct fittings. I really appreciate your help!
 
Can someone tell me how I can remove my original post? I have the answers I need and it seems like it is a waste for others to keep posting answers. Thanks for the help.
 
Hasn't it occurred to you that others might be interested in the thread, either now or in the future? Someone else has just asked the same question :
thread281-84751
Now all one has to do is refer them to your thread (which I did). If your thread were erased, that's what would waste people's time, since it would all have to be repeated!
 
These threads have many names, depending upon the country of origin but most of them agree:

BSPP = ISO(G) = cylindrical pipe thread with 55°apex angle

BSPT = ISO(R) = conical pipe thread with 55° apex angle


Alex
 
Hay, I'm from Belgium(Europe, maybe Brussels or Antwerp, says more to the most of you)
This is aal about pipe threads:
As far as I can check:
for example:
G 1/2 (for the female)
G 1/2 A (for the male thread add a tolerance class A(medium) or B(coarse))
means:
DIN ISO 228 Part 1: cilindrical male & female with nominal dimensions
This parallel thread is not used with a seal on the thread(use a sealing washer & flange)
or with other words:
apex angle= 55³
OD=20,955mm
TPI=14
or Pitch p=1,814mm
Thread Depth h=1,162mm
Pitch Dia d2=19,793mm
Root Dia d1=18,631mm
__________________________________________________________________________________
R 1/2 (for the male thread)
Rp 1/2 (for the female thread)
means:
DIN 2999 DIN 3858
WhitWorth pipe thread with parallel female(Rp) & tapered male(R) threads
This parallel thread is not used with a seal on the thread(use a sealing washer & flange)
or with other words:
apex angle= 55³
OD=20,955mm
TPI=14
or Pitch p=1,814mm
Thread Depth h=1,162mm
Pitch Dia d2=19,793mm
Root Dia d1=18,631mm
__________________________________________________________________________________
BSW-British Standard Whitworth for example 1/2"BSW
BSF-British Standard Fine for example 1/2"BSF
BSP-British Standard Pipe for example 1/2"BSP
(if BSP-British Standard Pipe Parallel is used it is in fact the same as: BSPP for example 1/2"BSPP)
BSPT-British Standard Pipe Tapered for example 1/2"BSPT
are all British Standards
and are not defined in the DIN or ISO norms as named above.
___________________________________________________________________________________
And I think I do not have to say that:
NPSM-National Pipe Straight Mechanical
NPSF-National Pipe Straight Fuel
NPT-National Pipe Taper
NPTF-National Pipe Taper Fuel
threads are all American standards.
_____________________________________________
So, I hope I helped with this.
If some one knows more let us know.
_____________________________________________
By the way:In Europe we use steel pipes and copper pipes as well for water as for gas,
depending on the kind of connections....
and , yes we use "hennep" and a kind of paste, but also "teflon"...

Greetings from Belgium (Europe).
 
Hay, again, i took some time to try to clear out this item.
It's quit complex.
Let's look at the "G" and "R" used in these thread designation.
By all means we are talking about a Whitworth shaped thread.
apex angle=55³
And it's about tubes or pipes, that's also clear.
Where comes this "R" from?
I think it comes from the German word for tube(or pipe): Rohr.
Where comes this "G" from?
I think it comes from the word Gas or it may come from the German word for thread: Gewinde

Designation "R" is used in:
DIN 259
Whitworth pipe threads: parallel internal and parallel external threads, basic sizes
and is linked (in this norm) to the earlier named: ISO 228
(in which the designation "G" is used)

Designation "R" is also used in:
DIN 2999
Pipe threads of Whitworth form: parallel internal and taper external threads

DIN 3858 is linked with DIN 2999 and is also about
Pipe threads of Whitworth form: parallel internal and taper external threads

I also found an old sheet in which a BSP was also designated with that "R" and
also with KR(BSPT):
It seems that "R" as well as "Rc" is used for BSPT in BS 21 (British Standard)

Designation "G" is used in:
BS 2779 for BSP (BSPF)

NOTES:
In this forum I noticed a link:
in which "G" is used for parallel Whitworth form threads: BSPP and BSPF
and where "R" is used for taper Whitworth form threads: BSPT

Look at this, different again(angle 60³ I think that this is a mistake):

Our question is not new, see this forum link:

And this is what i found also:
In March 2003 the British Standards Institute withdrew BS-2779 and replaced it
with ISO-228 (technically: BS-EN-ISO-228). The statement is that all requirements
for BS-2779 will now be filled with ISO-228.
So in the end, it's still not clear to me what is what.
The "G" en "R" are than used here, than used there, it's a kind of mixed up.

Greetings from Belgium (Europe).
 
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