What do these welding symbols mean?
Welding symbols are a set of information conveyed by the design department to the welding Engineer and the welding operator. It contains all the necessary information viz. welding position, dimensions and geometry of the weld, details of groove/fillet, welding process, etc. Arrow Line: Arrow indicates the position of the joint.
How to read basic welding symbols?
Welding Symbols and How to Read Them
- Welding Symbol Structure. Welding symbols are drawn in such a way that they provide a lot of information in a little space. ...
- Types of Welds. In the center of the reference line, you will see lines or a geometric shape that indicates what type of weld is required.
- Letters on Welding Symbols. ...
- Dimensions and Angles. ...
What is the symbol for welding?
The most important symbols that you do have to memorize are the fillet weld symbol and the groove weld symbol. You are more than likely going to come across welds on engineering and fabrication drawings. These are a set of symbols that describe the weld, the weld leg size, as well as giving processing and finishing information.
What is a weld symbol?
A weld symbol would differentiate between two sides of a joint using arrows and the spaces on top and under the reference line. You would create the weld based on the instructions under the reference line. If you need help with weld symbols and welders, we have an extensive guide on the structure and the different types below.
Why is welding symbol important?
Welding symbol is a very well-drafted language to master for better employment worldwide. Most welders have a hard time interpreting welding symbols and the market is running short of trained welders.
What does the arrow between two points mean?
Weld between points symbol – The drawing shows two points that require welding. The arrow between two points indicates the full-length welding between the marks.
What is a plug weld?
Plug Weld – The two plates are used here one with a hole that sits on another plain metal plate. The plug weld fuses the 2 plates together by joining at the hole. The plug weld symbol displays the plughole in a cross-section vista of the top metal plate.
What is the display of the symbol that shows a curve outwards like a balloon from the weld?
Convex – The display of the symbol shows a curve outwards like a balloon from the weld surface.
What is a backing weld?
Backing weld – The bottom of the weld preparation for V or U, it performs initial small weld at the bottom. This will add a substance to the complete weld. The symbol of it is a curved line beneath or on the top-tier of the base symbol, depending upon the side of the baseline.
What is resistance spot weld?
Resistance spot weld – The symbol is a circle similar to the shape of any spot weld. We create the spot with electrical resistance heat.
What is base platform welding?
The base platform is a simple depiction of the welding and surrounding details in three parts.
What are the different types of welds?
Such simple fillet weld, weld with defined length, staggered weld, full penetration groove weld
What is welding symbol?
A Welding symbol is different from a weld symbol; which is a graphic character connected to the reference line of a welded symbol specifying the joint geometry. So basically, the weld symbol is a part of the welding symbol. A full welding symbol consists of an arrow line, reference line, welding symbol.
Why are welding symbols important?
Importance of Welding symbols: Welding symbols are the integral part and the basic requirements for fabrication as they provide vital information for the joint location, weld size & length, weld type as well as quality requirements on the fabrication or construction drawing. The scheme for the symbolic representation of welds on engineering ...
What is the horizontal line on a welding symbol?
The horizontal line also called the reference line on which other welding symbols are placed. The instructions for weld are written along the reference line. An arrow line connects the reference line to the joint that is to be welded. The tail of the weld symbol is the place for supplementary information on the weld. It may contain a reference to the welding process, the electrode, a detailed drawing, or any information that aids in the making of the weld that does not have its own special place on the symbol.
What is a backing weld?
A backing weld is made on the root side of a groove in order to ensure that the weld that is going to be made in the groove from the face side does not melt through the backside. This may also help ensure CJP weld.
What is the tail symbol on a weld?
The tail of the weld symbol is the place for supplementary information on the weld. It may contain a reference to the welding process, the electrode, a detailed drawing, or any information that aids in the making of the weld that does not have its own special place on the symbol.
How many sides does a welding arrow point on?
We usually notice in drawing that there are two sides to the joint to which the arrow points, and hence two possible places for welding. For example, when two steel plates are joined together into a T shape, welding may be done on either side of the T joint as shown in the below figure.
What is a supplementary weld symbol?
Supplementary weld symbols are symbols that are added to the main weld symbol for more explanation, instruction, or knowledge. Sometimes you need the supplementary symbol to be added to the main weld symbol so that it can be properly understood. There are different types of supplementary symbols.
What does the spot weld symbol mean?
The spot weld symbol is indicated by a circle, so it’s pretty easy to understand. It can be placed below, above, or right on the reference line. If you have the spot weld symbol on the reference line, it means that there is no side significance, which means that you can apply it with a resistance spot welder used in sheet metal work.
Why are weld symbols important?
One of the reasons why weld symbols are important is that they make sure you have consistency and high quality whenever you construct or engineer. It would make it easy for welders to figure out where to put their welds, how large they should be, and what kind of weld they should use.
How to figure out where a plug weld is?
You can figure out the location of the plug weld by the centerline.
What is a fillet weld?
Fillet weld is used to make corner joints, lap joints, and T joints. The fillet weld symbols are usually triangular in the cross-section, and its shape is usually not an isosceles or right triangle, but it is a triangle either way.
What is a weld symbol?
A weld symbol would differentiate between two sides of a joint using arrows and the spaces on top and under the reference line. You would create the weld based on the instructions under the reference line.
How to identify a field weld?
You can identify the field weld by the flag symbol, which is at the point where the arrow and reference lines meet. When you see a field weld, it signifies that that part would be assembled in the shop setting. The point of the flag must point towards the direction of the end of the reference line.
Why are the edges of a V groove weld chamfered?
The edges of the V groove weld are to be chamfered in order to make a V-shaped opening between the pieces where the weld gets deposited. The symbol can hold multiple variables like the angle between the pieces, root opening, weld penetration and preparation, and of course any additional information in the tail.
What is the insert welding symbol?
If an insert is used within a welded joint that needs to become a part of the weld it is designated using the consumable insert welding symbol. This symbol should have a specified shape, size and material. Similar to the two above, this symbol is also placed on the opposite side of the groove weld symbol.
What is groove welding?
Groove is one of the most common welds you will come across in your welding career . It is often used to weld edge-to-edge joints but that is not where its use ends. This joint configuration can be used with T joints, corner joints, joints binding flat and curved elements, and so on.
What is the most commonly used welding symbol?
The table presents some of the most commonly used welding symbols. Fillet – The most used weld. Groove – Second most used. It usually involves preparing the edge pieces to form one of the groove weld shapes like V, bevel, U, J, Flare V, Flare bevel or no preparation at all with square edges to form a square groove.
What is reference line welding?
Reference lines are important welding symbols drawn as a straight line horizontally across the drawing. The reference line arrow also contains additional details about the welding itself. It can contain some valuable information like the joint design, the weld pattern, the weld size, etc.
What does the S size mean in welding?
The S (size) is mostly used with the fillet and groove welds and so is the E (Effective groove size or Effective throat). The size represents the leg size of the weld in fillet welds. It also represents the depth of preparation in groove welds. The E is used to designate the actual depth of penetration in groove welds.
What is the tail of a weld?
The tail is the third weld symbol part. It is drawn at the end of the reference line opposite the arrow. It usually contains information for which there is no provision elsewhere. The tail can provide info about the welding process, the reference document, and the examination process.
What is an inch mark?
Inch marks are used for indicating the diameter of arc spot, resistance spot, and circular projection welds, and the width of arc seam and resistance seam welds when such welds are specified by decimal dimensions. In general, inch, degree, and pound marks may or may not be used on welding symbols, as desired. 3-14.
What are the two types of break lines?
There are two kinds of break lines: short break and long break. Short break lines are usually heavy, wavy, semiparallel lines cutting off the object outline across a uniform section. Long break lines are long dash parallel lines with each long dash in the line connected to the next by a “2” or sharp wave line. 3-4.
What are break lines?
Break lines are used to show a break in a drawing and are used when it is desired to increase the scale of a drawing of uniform cross section while showing the true size by dimension lines. There are two kinds of break lines: short break and long break.
What is a cutting plane line?
Cutting plane lines are dashed lines, generally of the same width as the full lines, extending through the area being cut. Short solid wing lines at each end of the cutting line project at 90 degrees to that line and end in arrowheads which point in the direction of viewing.
What are hidden lines made of?
Hidden lines are made of short dashes which represent hidden edges of an object. c. Center Lines (B, fig. 3-1). Center lines are made with alternating short and long dashes. A line through the center of an object is called a center line.
What is the purpose of drawing?
Drawings. Drawing or sketching is a universal language used to convey all necessary information to the individual who will fabricate or assemble an object. Prints are also used to illustrate how various equipment is operated, maintained, repaired, or lubricated.
How many elements are in a welding symbol?
The assembled “welding symbol” consists of the following eight elements, or any of these elements as necessary: reference line, arrow, basic weld symbols, dimensions and other data, supplementary symbols, finish symbols, tail, and specification, process, or other reference.
What is a J shape weld?
This is an interesting type of preparation because it is the opposite of the flare bevel groove. The plate has one square end while the plate’s other end has a shape like a quarter circle. However, it has the opposite curvature of a flare bevel groove that allows the use of more welding material for the connection. In this way, a J shaped weld is made. It can also be seen in the symbol of the Single J joint given in figure 9.
What is flare groove welding?
A flare bevel groove is a unique way to prepare the welding area by making a 90-degree arc. On one of the sheets that need to be welded the edge is smoothened by this arc. The symbol of the single bevel joint is shown in Figure 8. The symbols take the shape of both pieces of metal.
What is single sided joint?
Those joints that are only welded at one side are known as single-sided joints. There are 7 major types of single-sided joints. There are more symbols but the rest of them is a combination of these. All of these single-sided joints with their symbol and weld preps are given below.
What does welding symbol mean?
If the welding symbol is on the dashed line, it means that welding will be performed on the opposite side of the arrow line. Similarly, when the welding symbol will be on the reference line, it means that welding will be performed in the same direction as described by the arrow line.
What does the symbol "Z" mean on a plate?
When the weld is required to be staggered intermittent between the plate’s two different sides, this symbol is used. This symbol also indicates that weld along the full length is not required. A line passing through Z is used as a symbol to indicate such a situation. The symbol and other details are shown in figure 23.
What is the V groove on a metal sheet?
It’s a common welding preparation on many occasions. In this case, there are two V grooves on each side that are meeting halfway along with the metal’s thickness. In this way, an X shape is developed along with the metal’s thickness. You can see a V-groove on both sheets symbol in figure 13.
What is the opposite of the concave symbol?
The symbol of the concave is curved in the opposite direction of the convex symbol. As it is opposite to the convex symbol, it can be deduced that weld is required to be finished in the inward direction. Fillet welds are used to obtain such type of finish. Details are given in figure 16.
Welding Symbols
The Base Platform
- The base platform is a simple depiction of the welding and surrounding details in three parts. 1. The horizontal reference line – The place to put details of type and location of welding 2. The arrow with the leader line – The arrow with the leader line intersects the reference line to point the location of the welding. 3. The tails line – It is at the other end of the reference line and forks off …
Two Types of Drawing Systems
- Two systems of base symbols drawing are handy and each explained differently. A plan will have a clear mention of system A or B but definitely not both in one draft.
System A
- System A is characterized by a dashed line below the horizontal reference line. The image here displays the welding symbol on the dashed line, so place the weld opposite to the arrow. Welding symbol above the reference line is advised to place the weld on the side of the arrow.
System B
- System B does not have any dashed line under the horizontal reference line. When you see the welding symbol below the reference line the welding to place on the side of the arrow. If we notice the weld sign is above the reference line the welding to be done opposite to the arrow.
Base Butt Symbols
- Once two plates sit flat and aligned straight and parallel by butting to one another end to end. These joints are two types. 1. Single-sided Butt Welds 2. Double-sided Butt Welds
Other Base Symbols
- The commonest type of joining is by butt welds and fillet welds. Contrary to butt welds the fillet welds exhibit the supplementary symbols compute additionally to fillet weld. We have the following base welding symbols which are not butt weld, including the fillet weld symbol. Fillet –This is roughly a triangular cross-section. It deposits the metal in a corner of the fit-up of two s…
Supplementary Symbols
- These symbols further clarify the welding characteristics, how and where to weld, and what is the final finishing need of the weld in a project. Flush Finish – This symbol explains what we need when finishing the process. The surface should be in a straight line with the level of the plate. This can be gained by machining or grounding of the weld joint. Convex – The display of the symbol …
Designations of Welding Processes by Letters
- When the symbols related to the welding process need clarification on the draft, then the letter designations require. We place these letter designations on the tail of the horizontal line. When no specification, process of welding, the tail should be omitted as below You Might also Enjoy… 12 Different Types Of Welding Processes [The Definitive Guide] 4 Best Ways For Stainless Steel Wel…
Final Words
- I have enumerated step by step as a guide to learn the welding symbols. By this time you are confident that this language of communication between planners and workmen is not difficult. We have completely grasped it for the project. Download the pdf version of this welding symbol guide for ready reference. Most welding machines come with a commonly used chart inside the frame…