Welding Symbols

[lazer]

Hi All,

Just a general question to get feedback on the current members.

If asked to weld to the welding symbols stated on the technical drawing do you find them easy to understand? Have you ever experienced any issues?

Kev

 

[Richard.]

Yes. I've done my fair share of working to and even producing welding drawings. It's daunting to look at for the first time with those symbols, letters arrows and dotted lines etc but you soon familiarise to them. Google images is good for showing what all the symbols and letters mean. There are literally hundreds and in some cases I forget and have to refer.

 

[Hitch]

Most are pretty easy to understand, and quite common.
There are a few ways of showing the same thing in some cases, which can be confusing, usually someone has used outdated or superceded standards.
Some need to be read with a supplementary sheet from time to time.
Then theres the jobs where someone covers a drawing in weld symbols that has no clue what they really mean.

 

[Richard.]

They do need to be studied carefully otherwise mistakes are easy to make. A lot of the symbols look similar and like hitch said there are ways of showing the same thing. The Common mistake I've seen and heard is the weld being put on the wrong side.
The arrow will always be shown from the right. And in cases when one weld is displayed eg a 7mm fillet. If it's placed above the line it goes on the far side below the line is arrow side. To someone who reads it logically it can look like it goes on the side it's pointing to so be careful with that.

 

[Richard.]

Yes and no.
The drawings you referred to in college will of been exactly as you said as they will of had a reference line and dotted line and as you say the symbol on the top ref line shows to be welded on the arrow side. So you are correct. Most of the drawings I had to work too were aws and this is the opposite to what you say and there is not a dashed line. This is when it gets complicated.

 

[Richard.]

I should of been more clearer as to the type or standard I was talking about. Above shows aws

 

[Richard.]

This is a good explanation of a bs standard meanings. (a is throat thickness and I believe 11 is gasless mig but I can't be sure of that).

 

[TurtleDude]

I feel a bit of a twit, as I came here expecting to find out how to make my own set of Zildjian symbols for a drum kit lol..

 

[Richard.]

I used to work for an American owned company and this made it difficult because drawings that were shared through email had to be produced and understood to AWS but in house drawings were quite often BS. To be fair there isn't a huge amount of differences but the symbols on the sides of the ref line could throw you. Easy thing to mess up. If there is a dashed line then top is arrow side. If it's just one reference line then top is other side.

 

[Kent]

A tip if your not sure ask (pick up the phone and check) or look it up (then reference were you looked it up), in fact if you don't work from such drawings fro a particular customer a lot you might do both. There are likely as many skilled welders who hardly ever use of them as those that do. If your producing a drawing also consider notes in place of symbols if practical to account for this. Most of my stuff is "fag packet" type sketches, sometimes I do my own scale drawings on the board old world perhaps but they are very fabricator friendly and I have never had trouble from any subcontractor in their interpretation ( the older guys often like the fact they have what is a better "working" type drawing they can use on the shop floor).
over use of computers by the inexperienced, trying to look clever instead of making things clear also randomly executed copy/paste are all crimes that should carry a stiff sentence of hard labour IMO.
Given a complicated drawing I cant be alone in sitting down and producing a simplified working plan or series of plans and cutting lists, order of assembly to take into the shop.

I cant be 100% sure because its been years from the times I did this daily and like has been said things change, I just chucked my notes out from the 80s that lived in the top of an old tool box for this very reason as has been mentioned, in the library I have plenty development layouts, drawing notes and various technical info because we all need to work outside our regular comfort zones time to time. Why do you think I kept those notes in the top of my box so long? because one day it will prevent error if you check everything through and biro in some notes on a copy plan

 

[Richard.]

General fabrication drawings Are enough as the guy building it knows where and how to put the welds on so there is no need for extra work and complications by adding more levels of paperwork in cases like this. I used to fabricate a lot for the cement and power industry and make components out of wear plates and install a lot of them on site all over the world. The type of weld and position was critical in this case as the weld was not supposed to wear before the components life was up. If it did then it would fall apart and smash the insides of the machine while it was running. This was then designed to have the welds in places less vulnerable to wear And in a lot of cases hard facing was done on top of the welding to help further. The drawings then had to be followed properly in this case. Like I say I'm no expert and a bit out of practice now so when the question does arise like yourself Kent the notes are often referred too.

 

[Dimitri De Spiegeleer]

Here's something that might clear up some things:
(you either use system A, with the dashed lines, or system B, without those dashed lines. Doesn't matter, but you have to be consistent)

Richard, what standard/year does your extract comes from? Never seen drawings with references in the tail that don't say what kind of references they are.
Normally, there should be both the procedure or standard + the detail that the draftsman wants to emphasize, in the tail.
See attached screenshot, from the EN ISO 2553 : 2013
you see amongst others quality level C according to ISO 5817 in the open tail example
or a reference to a general note "A1" in the closed tail.
(like, "A1: all welds to be made in position PB")

 

[Richard.]

The explanation I found on the net the standard was not quoted as I believe it is for example of what means what when looking at a typical reference. Hence the numbers and brief explanations. I thought it was a good little sketch to put up as it simplifies what things mean. It's a good spot though I would of thought it would have been shown as a closed end and explained that a separate reference was to be seen for quality, process, position etc.
it's been a while now I haven't used them as I once did For a number of years so I'm bound to be out of practice and miss certain things.

 

[Rocketman]

Almost as bad as 1st and 3rd angle projection drawings...Though I find 3rd angle more "natural"...

Go back to the USA with your 3rd angle drawings

 

[Kent]

Here's something that might clear up some things:
(you either use system A, with the dashed lines, or system B, without those dashed lines. Doesn't matter, but you have to be consistent)

Richard, what standard/year does your extract comes from? Never seen drawings with references in the tail that don't say what kind of references they are.
Normally, there should be both the procedure or standard + the detail that the draftsman wants to emphasize, in the tail.
See attached screenshot, from the EN ISO 2553 : 2013
you see amongst others quality level C according to ISO 5817 in the open tail example
or a reference to a general note "A1" in the closed tail.
(like, "A1: all welds to be made in position PB")

NOW can we all see how simple these things are to follow? Sometimes (actually quite often) I despair. remember also that standards and std numbers are not only numerous but changing BS, ISO,EN and all of it costs money one way or another. Its good of you to post this BTW not getting at you and what you get paid for.

On a drawing not requiring the above Mark up" 7mm fillet this side" etc. and I bet you nobody makes an error

 

[Richard.]

Kent if I wrote that on a drawing and sent it to another country or someone that can't read English or my scruffy writing then it's not that straight forward. Symbols and welding drawings are understood World wide by people who work to them.

 

[Wedg1e]

over use of computers by the inexperienced, trying to look clever instead of making things clear also randomly executed copy/paste are all crimes that should carry a stiff sentence of hard labour IMO.

I've just been designing and building a machine for inspecting 30mm ammunition and most of the parts were made by a local machine shop to my drawings; when I was talking to the machinists over there they were comparing my no-nonsense specifications with some other customers who clearly have too much time on their hands with AutoCAD and have all manner of chamfers, fancy radii, countersinks, counterbores... a lot of which (especially the rads and chamfers) are just for show - but the actual thing they've designed is pants anyway! They showed me a cast lead storage container for radioactives that had a solid lead lid with no manner of restraining it while open (so it'll fall backwards and likely bend the hinges if dropped), a padlock hasp and staple that interfered with your ability to pick the thing up etc etc... my bits tend to be nice shapes with as few holes or pockets as necessary to do the job and if it needs a chamfer, I'll file it on afterwards