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[[File:Symboles soudure V.svg|300px|thumb|right|The symbolic representation of a V weld of chamfered plates in a technical drawing]]
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The '''symbols and conventions used in [[welding]] documentation''' are specified in national and international standards such as [[International Organization for Standardization|ISO]] 2553 ''Welded, brazed and soldered joints -- Symbolic representation on drawings'' and ISO 4063 ''Welding and allied processes -- Nomenclature of processes and reference numbers''. The US standard symbols are outlined by the [[American National Standards Institute]] and the [[American Welding Society]] and are noted as "ANSI/AWS".<ref name=greg>{{cite book|author1=E. N. Gregory|author2=Ann A. Armstrong|title=Welding symbols on drawings|url=https://books.google.com/books?id=X9cxdD6GfdIC&pg=PR7|accessdate=10 October 2011|date=20 April 2005|publisher=CRC Press|isbn=978-0-8493-3591-4|pages=7–8}}</ref> Due in part to the growth of the oil industry, this symbol set was used during the 1990s in about 50% of the world's welding operations.<ref name=greg/> An ISO committee sought to establish a global standard during this decade.<ref name=greg/>
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[[File:Symboles soudure V.svg|thumb|right|The symbolic representation of a V weld of chamfered plates in a technical drawing]]
The '''symbols and conventions used in [[welding]] documentation''' are specified in national and international standards such as [[International Organization for Standardization|ISO]] 2553 ''Welded, brazed and soldered joints -- Symbolic representation on drawings'' and ISO 4063 ''Welding and allied processes -- Nomenclature of processes and reference numbers''.
{{clear}}
[[File:SMAW weld area.svg|thumb|left|Welding]]
[[Welding]] is the process of joining similar or dissimilar metals by the application of heat and sometimes pressure. Many techniques and methods are used general and specific purposes. Different types of joint include the square butt joint, single V preparation joint, lap joint and T-joint.
[[File:Common joint types.png|thumb|right|Joint types]]


In [[engineering drawing]]s, each weld is conventionally identified by an arrow which points to the joint to be welded. The arrow is annotated with letters, numbers and symbols which indicate the exact specification of the weld. In complex applications, such as those involving [[alloy]]s other than [[Carbon steel|mild steel]], more information may be called for than can comfortably be indicated using the symbols alone.<ref name=greg/> Annotations are used in these cases.<ref name=greg/>
These different types of welded joint are represented by symbols which are similar to the shape of welds. These symbols are categorised as:


==Component elements==
*Elementary symbols
[[File:Elements of a welding symbol.PNG|thumb|right|350px|The location of the elements of a welding symbol when following US conventions.]]
*Supplementary symbols
In the US, the component elements of the weld specification are:<ref name=TC9237>{{citation |title=Welding Theory and Application |publisher=Department of the Army |date=7 May 1993 |number=Training Circular 9–237 |url=https://armypubs.us.army.mil/doctrine/DR_pubs/dr_aa/pdf/tc9_237.pdf}}</ref>
*Combinations of elementary symbols
# The reference line - the body of the arrow which is the baseline for the specification.
*Combinations of elementary and supplementary symbols
# The arrow tip which goes at an angle to the reference line, pointing to the joint to be welded.
# The tail which goes at the other end of the reference line.
# The basic welding symbol which goes on the reference line to indicate the shape of the weld such as a fillet or plug. The symbol is placed on the arrow side or other side of the line to indicate which side of the joint the weld goes.
# The dimensions and other numbers such as the length of the weld or number of spot welds go above and below the reference line.
# Supplementary symbols go at the junction of the reference line and the arrow tip. One such symbol is a circle to indicate an all-around weld, which goes on every side of the joint.
# Finish symbols go above the reference line to indicate the surface contour or finish of the weld such as flush, convex or concave.
# Letters indicating the welding process are placed at the tail end, such as AHW for [[atomic hydrogen welding]]. Further examples include:
==Abbreviations for welding processes==
{{Main|List of welding processes}}
If a particular welding process needs to be indicated in addition to the symbols, the following abbreviations are commonly used in North America:<ref>"Welding Inspection Handbook", 3rd edition, [[American Welding Society]], {{ISBN|0-87171-560-0}}, Miami, FL, pp. 10-11 (2000)</ref><ref name=TC9237/>


{| class="wikitable sortable" style="text-align:center; width:50%;"
==Elementary Welding Symbols==
The elementary symbols are as follows:<br>
[[File:AJINKYA (cropped).jpg|center]]

==Supplementary Welding Symbols==
These symbols are used with elementary symbols to show the finishing of the weld joint. Such as flatness, convexity, concavity etc.

==Conventional Signs==

*'''Bureau Of Indian Standards (BIS'''):
According to this standard the welding all around the joint is represented by
# using a hallow circle
# using a filled-in circle
at the elbow (connecting corner of the arrow and reference line).
*'''International Standards Organization(ISO)''':
This convention indicates the process of welding used.To represent this the 90°V is formed at the tail end of the arrow and the name of process is written in that.

==Location of welds==
The location of welds is specified by the following:
# Position of the arrow line
# position of the reference line
# position of the symbol
====Position of the arrow line====
The arrow line joins one end of the continuous reference line in such a way that it forms an angle with it and is completed by an arrow head.
The adjoining figure shows the relation between the arrow line and the joint. 'Arrowside' and 'otherside' are the two terms which are used with respect to the continuous plate.
[[Category:Welding]]
The position of the arrow line with respect to the weld is not significant. But, in the case of edge preparation, the arrow line points towards the plate which is prepared.

====Position of the reference line====
The reference line should be drawn parallel to bottom edge of the drawing and if it is not possible; then it should be drawn perpendicular.
====Position of the symbol====
The position of the symbol is either above or beneath the reference line.
If weld is on the arrow side of the joint or on the dashed line side,then symbol is placed on the continous side of the reference line.

==Rules to be observed while applying symbols==
# The symbols for fillet and similar welds are to be shown, such that the vertical position of the symbols are indicated on the left hand side of the symbol, irrespective of the orientation of the weld symbol.
# If the welds are to be made on the arrow side of a joint, the corresponding welding symbol should be placed either above or below the continuous reference line.
# If the welds are to be made on the other side of a joint, the corresponding welding symbol should be placed either above or below the dashed reference line.
# If the welds are to be made on both sides of a joint, the corresponding symbols should be placed on both sides of the reference line and the dashed line is not shown.
# The arrow of the symbol must point towards the joint which requires welding.
# When only one member is to be edge prepared to make the joint, the arrow should point at that plate.
# Dimensions of size are indicated in mm without writing the unit mm. The letter 'a' or 'z' is placed in front of the value of the fillet size, depending upon whether the throat or leg and length of the weld is shown on the right hand side. If no length is given, it implies that full length is to be welded.
# If unequal legs of are to be used, they should be given on the left hand side.
# If the weld is to be made all around a joint, a circle should be placed at the elbow, connecting the arrow to the reference line.
# If a weld is required to be made on the site or during assembly or erection, it is represented by a filled-in circle at the elbow, connecting the arrow and the reference line.
# If the weld is to have a flush or flat finish, a straight line should be added above the symbol.
# The welding process is indicated at the end of the arrow, if required.
==Welding process designation==
While,representation of welding symbol it is necessary to have some abbreviations for simplicity and to avoid lengthy notes.
*welding process designation as follows
{| class="wikitable"
|-
|-
! Designation!! Welding process
! Designation!! Welding process
|-
|-
| CAW || Carbon arc welding
| CAW || [[Carbon-arc welding]]
|-
|-
| IB || Induction Brazing
| DB || [[Dip brazing]]
|-
|-
| CW || Cold welding
| FB || [[Furnace brazing]]
|-
|-
| IRB || Infra red brazing
| FW || [[Flash welding]]
|-
|-
| GMAW || [[Gas metal arc welding|Gas metal-arc welding]]
| DB || Dip brazing
|-
|-
| OAW || Oxy-acetylene welding
| GTAW || [[Gas tungsten-arc welding]]
|-
|-
| DFW || Diffusion welding
| IB || [[Induction brazing]]
|-
|-
| OHW || Oxy-hydrogen welding
| OAW || [[Oxy-acetylene welding]]
|-
|-
| EBW || Electron beam welding
| OHW || [[Oxyhydrogen welding|Oxy-hydrogen welding]]
|-
|-
| PGW || Pressure gas welding
| PGW || [[Pressure gas welding]]
|-
|-
| RB || [[Brazing#Heating methods|Resistance brazing]]
| ESW || Electro-slag welding
|-
|-
| RB || Resistance welding
| SAW || [[Submerged arc welding]]
|-
|-
| EXW || Explosion welding
| SMAW || [[Shielded metal arc welding]]
|-
|-
| TB || [[Brazing#Heating methods|Torch brazing]]
| RPW || Projection welding
|-
|-
| FB || Furnace welding
| UW || [[Upset welding]]
|-
| RSEW || Resistance seam welding
|-
| FOW || Forge welding
|-
| RSW || Resistance spot welding
|-
| FRW || Friction welding
|-
| RW || Resistance welding
|-
| FW || Flash welding
|-
| SAW || Submerged arc welding
|-
| GMAW || Gas metal arc welding
|-
| TB || Torch welding
|-
| GTAW || Gas tungsten arc welding
|-
| UW || Upset welding
|}
|}

==References==
==References==
{{reflist}}
{{reflist}}

==Further reading==
* {{Cite book
* {{Cite book
| author = K.L.Narayana,P.Kannaiah,K.Venkata Reddy
| author = K.L.Narayana,P.Kannaiah,K.Venkata Reddy
Line 132: Line 63:
| title = Machine Drawing
| title = Machine Drawing
| publisher = New age International
| publisher = New age International
| isbn =978-81-224-1917-7
| isbn =978-81-224-1917-7
}}
}}
* {{Cite book
* {{Cite book
Line 138: Line 69:
| year = 2003
| year = 2003
| title = Machine Drawing
| title = Machine Drawing
| publisher = Charotar Publishing House
| publisher = Charotar Publishing House
| isbn = 81-85594-19-8
| isbn = 81-85594-19-8
}}
}}

==External links==
*[http://www.arcraftplasma.com/welding/AWS-welding-symbols.pdf Welding symbols] at Arcraft Plasma Ltd.
*[https://web.archive.org/web/20111109234545/http://www.metallicfusion.com/symbols_and_definitions.htm Welding symbols and definitions] at Metallic Fusion
*[http://www.engineersedge.com/weld_symbol.htm Standard welding symbols] at Engineer's Edge
*[http://www.download-it.org/free_files/filePages%20from%2026.%20Welding%20and%20welding%20symbols.pdf Extract from Chapter 26 – Welding and welding symbols] in ''Manual of Engineering Drawing'' by Colin H. Simmons and Dennis E. Maguire. Newnes (2004). {{ISBN|0-7506-5120-2}}


[[Category:Notation]]
[[Category:Standards]]
[[Category:Welding]]

Revision as of 19:48, 10 June 2023

The symbolic representation of a V weld of chamfered plates in a technical drawing

The symbols and conventions used in welding documentation are specified in national and international standards such as ISO 2553 Welded, brazed and soldered joints -- Symbolic representation on drawings and ISO 4063 Welding and allied processes -- Nomenclature of processes and reference numbers. The US standard symbols are outlined by the American National Standards Institute and the American Welding Society and are noted as "ANSI/AWS".[1] Due in part to the growth of the oil industry, this symbol set was used during the 1990s in about 50% of the world's welding operations.[1] An ISO committee sought to establish a global standard during this decade.[1]

In engineering drawings, each weld is conventionally identified by an arrow which points to the joint to be welded. The arrow is annotated with letters, numbers and symbols which indicate the exact specification of the weld. In complex applications, such as those involving alloys other than mild steel, more information may be called for than can comfortably be indicated using the symbols alone.[1] Annotations are used in these cases.[1]

Component elements

The location of the elements of a welding symbol when following US conventions.

In the US, the component elements of the weld specification are:[2]

  1. The reference line - the body of the arrow which is the baseline for the specification.
  2. The arrow tip which goes at an angle to the reference line, pointing to the joint to be welded.
  3. The tail which goes at the other end of the reference line.
  4. The basic welding symbol which goes on the reference line to indicate the shape of the weld such as a fillet or plug. The symbol is placed on the arrow side or other side of the line to indicate which side of the joint the weld goes.
  5. The dimensions and other numbers such as the length of the weld or number of spot welds go above and below the reference line.
  6. Supplementary symbols go at the junction of the reference line and the arrow tip. One such symbol is a circle to indicate an all-around weld, which goes on every side of the joint.
  7. Finish symbols go above the reference line to indicate the surface contour or finish of the weld such as flush, convex or concave.
  8. Letters indicating the welding process are placed at the tail end, such as AHW for atomic hydrogen welding. Further examples include:

Abbreviations for welding processes

Main article: List of welding processes

If a particular welding process needs to be indicated in addition to the symbols, the following abbreviations are commonly used in North America:[3][2]

Designation Welding process
CAW Carbon-arc welding
DB Dip brazing
FB Furnace brazing
FW Flash welding
GMAW Gas metal-arc welding
GTAW Gas tungsten-arc welding
IB Induction brazing
OAW Oxy-acetylene welding
OHW Oxy-hydrogen welding
PGW Pressure gas welding
RB Resistance brazing
SAW Submerged arc welding
SMAW Shielded metal arc welding
TB Torch brazing
UW Upset welding

References

  1. ^ a b c d e E. N. Gregory; Ann A. Armstrong (20 April 2005). Welding symbols on drawings. CRC Press. pp. 7–8. ISBN 978-0-8493-3591-4. Retrieved 10 October 2011.
  2. ^ a b Welding Theory and Application (PDF), Department of the Army, 7 May 1993
  3. ^ "Welding Inspection Handbook", 3rd edition, American Welding Society, ISBN 0-87171-560-0, Miami, FL, pp. 10-11 (2000)

Further reading

  • K.L.Narayana,P.Kannaiah,K.Venkata Reddy (2008). Machine Drawing. New age International. ISBN 978-81-224-1917-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
  • N.D.Bhatt,V.M.Panchal (2003). Machine Drawing. Charotar Publishing House. ISBN 81-85594-19-8.
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