of joint preparation
•Welding positions
•Other types of welds
•Welding terminology
•Welding cables
•Safety equipment
•Safety practices
Joint Types
What are the five basic joint types?
•Lap joint
•Butt joint
•Corner joint
•T-joint
•Edge joint
See Figure 4–1.
Figure 4–1Joint types
Joint Edge Preparation
Why is edge preparation done?
Joint preparation provides access to the joint interior. Without it the entire internal portion of the joint would not be fused or melted together making the joint weak. Remember that a properly made, full-penetration joint can carry as much load as the base metal itself, but full penetration will only occur with the correct joint preparation.
How are edge shapes for weld joint preparation made?
Usually, they are made by flame cutting, plasma arc cutting, machining or grinding however, castings, forgings, shearing, stamping and filing are also common methods used to prepare material for welding.
What edge shapes used in preparation for welding?
See Figure 4–2.
Figure 4–2Edge shapes for weld preparation
Edge Preparation Terminology
What are the principal parts of V-and U-groove joint preparations?
•Depth of bevel
•Size of root face
•Root opening
•Groove angle
•Bevel angle
See Figure 4–3.
Figure 4–3Parts of V- and U-groove joint preparations
Edge Shape Combinations
What are the most common combinations of joint preparations for butt joints?
See Figure 4–4.
Figure 4–4Single-groove and double-groove weld joint
What common preparations are used on corner joints?
See Figure 4–5.
Figure 4–5Weld preparation for corner joints
What weld preparations are used on T-joints?
See Figure 4–6.
Figure 4–6Weld preparations for T-joints
What are the weld preparations for edge joints?
See Figure 4–7.
Figure 4–7Weld preparations for edge joints
What are the weld preparations for lap joints?
See Figure 4–8.
Figure 4–8Weld preparations for lap joints
Selection of Joint Preparation
What determines which joint preparation geometry to use?
The factors are:
•Kind of joint loads (tension, compression, shear, or torsion).
•Level of joint loading.
•Static or dynamic loading.
•Thickness and type of the metals joined.
•Welding position.
•One side/both sides access to the weld.
•Skills of welders.
•Trade-offs between joint preparation costs/filler metal costs/welding labor costs; each joint and geometry carries its own combination of total cost.
What is an excellent source of weld joint design and preparation information for steel?
The Structural Welding Code—Steel, ANSI/AWS D 1.1 is a document with over 50 detailed drawings for pre-qualified joint designs using SMAW, GMAW, and FCAW for steel plate. Joints for submerged arc welding (SAW) are also included. There is additional information for joining tubing, weld testing, and inspection. The document is available from the AWS.
Joint Preparation
What are the most common weld preparations?
See Figure 4–9.
Figure
