Welding symbol

It means that the weld surface is to be machined flush.

There should be a standard symbols drawing somewhere as well, to enable the codes on any other drawing to be read. Otherwise, how does the drafter know what to put on the drawing in the first place (rhetorical question)?

Check for a drafting standards manual.

Also, the initials of the drafter, the checker and the approver will appear on the drawing somewhere; these are some people to ask.

Exactly. The purpose of a drawing is to communicate. How can one do that without the 'dictionary'?

"Also, the initials of the drafter, the checker and the approver will appear on the drawing somewhere; these are some people to ask."

Only in your dreams. If you do find them good luck making contact, and if you do make contact you will be very fortunate indeed if they understand the symbols themselves.

Sorry, I have seen way too many bad drawings. Maybe I should start a forum on what not to do on a drawing.

There are plenty of books and references on GDT (geometric dimensioning and tolerencing) and ANSI standards with explantions of drafting symbols. Machinery's Handbook also has this info.

'Sorry, I have seen way too many bad drawings. Maybe I should start a forum on what not to do on a drawing.'

I'll go with that. My experience is that since we have thrown away our drawing boards (metaphorically I hope!) and anyone and his dog can get a drawing package on the old PC causing standards to fall like a rock.

Symbol without M means flushing off the weld by any means grinding or machining and with M means weld to be machined flush

If the symbol is without M then it means weld to ground or machine flush. Symbol with M means weld to be machined flush.

According to ANSI/AWS A2.4-98, [Para. 13.3.2 Finishing Methods], the following finishing symbols may be used to specify the method of finishing, but not the degree of finish:

C - Chipping, G - Grinding, H - Hammering, M - Machining & R - Rolling

From now I understand this symbol. Thanks for every post.