welding symbol 6

[mfgenggear]

Please advise what this welding symbol means see attached

 

[dik]

It's a butt weld ground smooth...I don't know what the 'M' stands for.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[mfgenggear]

Dik thank you for the reply, could be NDT requirement

 

[DekDee]

Square groove butt weld welded all around with a flush/flat finish.
The M may stand for Mechanical as in grinding to achieve the flush / flat finish.
A bit strange as it shows a single sided joint with no backing ?

 

[mfgenggear]

thank you for taking the time to reply, stars for both of you

 

[kingnero]

Under EN/ISO, the M means material backing (could be metal, flux or ceramic backing but not gas backing). But it should be on the other side of the reference line...

 

[dik]

Thanks, king...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[kingnero]

I stand corrected, it's only base material or permanent backing (not flux nor ceramic).
See below table:

(f) M, material to be part of the final welded joint, MR, material to be removed after welding. Further information on the material can be included in the tail or elsewhere.

 

[dik]

again, thanks... gas backing? just air or inert gas. I've not encountered the use of the letter in any of the work I've done.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[mfgenggear]

kingnero

thank you for the reply and answer.

 

[DekDee]

Obviously dependant on where the OP is located and what code/standard he / she is working with.
This is from Australia

AS 1101.3
Graphical symbols for general engineering
Part 3: Welding and non-destructive
examination
2.3.7 Contour and surface finish methods for complete penetration from one side
2.3.7.1 Flush contour
Complete penetration welds from one side that are to be made flush by mechanical means
shall be shown by adding both the flush contour symbol and the required finish symbol to
the symbol for complete penetration from one side (see Clause 2.3.10 and Figure 2.15).

 

[gtaw]

Without knowing what the governing standard is, it a crap shoot trying to provide a definitive response.

Best regards - Al

 

[mfgenggear]

usa aws

 

[kingnero]

gas backing? just air or inert gas.

With gas backing, inert or semi-active (Nitrogen + hydrogen, which is fairly active even in small quantities) gas is generally meant.
Air = no backing, but I understand the premise.

@ gtaw, Clearly you are correct. For that purpose I explicitly mentioned EN/ISO.
I believe AWS A2.4 says something about Machining (M) (next to grinding, hammering, chipping, ...), but I see way too few AWS drawings to be able to confidently say something about that.

 

[david339933]

M = Machining....and gives only the method, not the degree of finish.

 

[mfgenggear]

thanks again

 

[dik]

ditto... dik

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

The M cannot be Machining, because any joint thin enough to permit CJP welding on a square groove will be too bent out of shape to machine.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[r6155]

Never use these types of welding symbols in detailed shop drawings. Use only fillet weld symbols.

Regards

 

[Demented]

The M cannot be Machining, because any joint thin enough to permit CJP welding on a square groove will be too bent out of shape to machine.

Sounds like you need to acquaint yourself with welders who know about clamps.

Precision guess work based on information provided by those of questionable knowledge