Tweco 175 SE Arc Master - Manuel (Page 31)

OpERATION ARC MASTER 175 SE
Manual 0-5054 4-5 OPERATION
4.12 Joint Preparations
In many cases, it will be possible to weld steel sections without any special preparation. For heavier sections
and for repair work on castings, etc., it will be necessary to cut or grind an angle between the pieces being
joined to ensure proper penetration of the weld metal and to produce sound joints.
In general, surfaces being welded should be clean and free of rust, scale, dirt, grease, etc. Slag should be
removed from oxy-cut surfaces. Typical joint designs are shown in Figure 4-10.
Figure 4-10: Typical joint designs for arc welding
4.13 Arc Welding Technique
A Word to Beginners
For those who have not yet done any welding, the simplest way to commence is to run beads on a piece of
scrap plate. Use mild steel plate about 1/4" (6.0mm) thick and a 1/8" (3.2mm) electrode. Clean any paint, loose
scale or grease off the plate and set it firmly on the work bench so that welding can be carried out in the down
hand position. Make sure that the work clamp is making good electrical contact with the work, either directly
or through the work table. For light gauge material, always clamp the work lead directly to the job, otherwise
a poor circuit will probably result.
Gap varies from
1.6mm (1/16”) to 4.8mm (3/16”)
depending on plate thickness
Joint
Open Square Butt
1.6mm (1/16” ) max
1.6mm (1/16”)
Single Vee Butt Joint Not less than
70°
Double Vee Butt Joint
1.6mm (1/16”)
Lap Joint
Tee Joints
(Fillet both sides of the
joint)
Edge Joint
Fillet Joint
Corner Weld
Plug Weld Plug Weld
Not less than
70°
Single Vee Butt Joint
Not less than
45°
1.6mm (1/16”) max
Art # A-07695_AE