1. Unit 212/255
Weld Joint Geometry
and
Weld Symbols

2. Welded joint geometry

3. Types of Joint
Tee joint
Butt joint
Lap joint
Corner joint
Edge joint

4. Types of weld
Tee fillet
Butt weld
Lap fillet
Corner fillet
Edge seam

5. Types of Weld Preparation
Double V butt
Single V butt
Single U butt
Double U butt

6. Fillet Weld Features Convex profile – nominal throat shown
Mitred profile
Concave profile – reduced throat
Throat size is an important consideration on fillet welds. Unless otherwise indicated on the drawing or welding specification it should be at least equal to the material thickness.
The examples shown all have the same leg length (z)
Convex profile – nominal throat shown

7. Butt Weld Features
Vee butt
J butt

8. Welding Symbols
To ensure that the size, shape and position of a weld is understood, a system of welding symbols are used on engineering drawings.
A common set of symbols are recognised throughout Europe.
BS EN 22553

9. Weld Symbols BS EN 22553
All the standards will have the same basic requirements which include an arrow line and head and a reference line.
Reference lines

10. A dotted line indicates the “other side” of the joint
Weld Symbols BS EN 22553
The designer indicates the required joint geometry by using symbols on the reference line
A dotted line indicates the “other side” of the joint 1 2 3 4 5
Single v butt joint
Single bevel joint
Double bevel joint
Double fillet joint
Single fillet joint

11. For resistance welding a spot and seam weld are shown:
Weld Symbols BS EN 22553
For resistance welding a spot and seam weld are shown:
Spot weld
Seam weld

12. Weld Symbols BS EN 22553
Double V face flushed flat
Additional information for the welder can indicate the finished shape of the weld.
Single V convex profile
Single fillet concave profile

13. Weld Symbols BS EN 22553 Fillet weld size
The correct size of weld is important to ensure sufficient strength.
BS EN 22553
a = throat size
z = leg length

14. Weld Symbols BS EN 22553 Intermittent (stitch) welds
Stitch weld information includes number of welds, length of weld and gap between welds.

15. Stitch welds on both sides of the joint can be shown by adding a Z
Weld Symbols BS EN 22553
Stitch welds on both sides of the joint can be shown by adding a Z

16. Weld Symbols BS EN 22553 Supplementary symbols
Other information can be added to the weld reference line.

17. Weld Symbols BS EN 22553 Welding process
Each welding process is identified within ISO 4063 by a reference number. In this example, 114 refers to MIG welding
Number
Welding process
111
Metal arc welding with covered electrode (MMA)
114
Metal inert gas welding (MIG)
135
Metal active gas welding (MAG)
137
Flux cored metal arc gas welding with inert gas
141
Tungsten inert gas welding (TIG

18. Process Identification BSEN 4063
Process terminology
BS EN ISO 4063:2000 Welding and allied processes - assigns a unique number to the main welding processes. These are grouped as follows:
Arc welding
Resistance welding
Gas welding
Forge welding
Brazing, soldering and braze welding
Each process is identified within the group by a reference number. For example, the MIG welding process has a reference number of 131 which is derived as follows:
1 - Arc welding
3 - Gas-shielded metal arc welding
1 - Metal arc inert gas welding

19. Process Identification BSEN 4063
The main arc welding process reference numbers are:
manual metal arc welding
114 self-shielded tubular-cored arc welding
121 submerged arc welding with one wire electrode
125 submerged arc welding with tubular cored electrode
131 metal inert gas welding (MIG welding)
135 metal active gas welding (MAG welding)
136 tubular cored metal arc welding with active gas shield
141 tungsten inert gas arc welding (TIG welding)
plasma arc welding