IDEF9 Standard

This engineering drawing shows different types of geometry of butt welds.
"Welds can be geometrically prepared in many different ways. The five basic types of weld joints are the butt joint, lap joint, corner joint, edge joint, and T-joint (a variant of this last is the cruciform joint). Other variations exist as well - for example, double-V preparation joints are characterized by the two pieces of material each tapering to a single center point at one-half their height. Single-U and double-U preparation joints are also fairly common - instead of having straight edges like the single-V and double-V preparation joints, they are curved, forming the shape of a U. Lap joints are also commonly more than two pieces thick - depending on the process used and the thickness of the material, many pieces can be welded together in a lap joint geometry." [Welding. Wikipedia]
This engineering drawing example was redesigned using the ConceptDraw PRO diagramming and vector drawing software from the Wikimedia Commons file: Butt Weld Geometry.GIF.
[commons.wikimedia.org/ wiki/ File:Butt_ Weld_ Geometry.GIF]
The engineering drawing example "Butt weld geometry" is included in the Mechanical Engineering solution from the Engineering area of ConceptDraw Solution Park.

"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".
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. Annotations are used in these cases." [Symbols and conventions used in welding documentation. Wikipedia]
The example chart "Elements of welding symbol" is redesigned using the ConceptDraw PRO diagramming and vector drawing software from the Wikipedia file: Elements of a welding symbol.PNG.
[en.wikipedia.org/ wiki/ File:Elements_ of_ a_ welding_ symbol.PNG]
The diagram example "Elements location of a welding symbol" is contained in the Mechanical Engineering solution from the Engineering area of ConceptDraw Solution Park.

This engineering drawing present weld type symbols and fillet weld symbols.
The weld type symbol is typically placed above or below the center of the reference line, depending on which side of the joint it's on. The symbol is interpreted as a simplified cross-section of the weld.
"Fillet welding refers to the process of joining two pieces of metal together whether they be perpendicular or at an angle. These welds are commonly referred to as Tee joints which are two pieces of metal perpendicular to each other or Lap joints which are two pieces of metal that overlap and are welded at the edges. The weld is aesthetically triangular in shape and may have a concave, flat or convex surface depending on the welder’s technique. Welders use fillet welds when connecting flanges to pipes, welding cross sections of infrastructure, and when fastening metal by bolts isn't strong enough." [Fillet weld. Wikipedia]
The engineering drawing example Welding symbols is included in the Mechanical Engineering solution from Engineering area of ConceptDraw Solution Park.