CAB GP 3980822 - Caterpillar

Illustration 144 g01989420
Stringer TechniqueNote: Use a 10 to 15 degree push angle for the stringer technique.
Illustration 144 represents the stringer technique of welding. The center of the arc needs to be 0.0 - 2.0 mm (0.0 - 0.08 inch) from the weld toe into the base material.
Illustration 145 g01989494
Weave TechniqueNote: Use a 10 to 15 degree push angle for the weave technique.
Illustration 145 represents the weave technique of welding.
Illustration 146 g01989613
Cross section of the proper TIG Dressing
Illustration 146 represents a cross section view of a proper TIG Dressed fillet weld.
Illustration 147 g01990055
View of a proper TIG Dressing
Illustration 148 g01990056
View of the proper TIG Dressing
Illustration 147 and Illustration 148 demonstrate the expected results.
Once TIG dressing is completed, the area needs to be cleaned and painted in order to prevent pitting due to corrosion.Note: Poorly shaped fillet welds with 70 degree to 90 degree transition angles will require several overlapping TIG dressing runs. Overlapping of the TIG dressing runs is required in order to stabilize the weld toe transition area.Note: TIG dressing can be conducted in the vertical position as long as the TIG dressing is performed in a downhill progression.Note: Some undercuts will require the addition of filler metal. Adding filler metal can be accomplished by hand feeding ER70S-2 1.5 mm (0.06 inch diameter) into the weld pool. You then repeat the TIG dressing in order to achieve the desired toe radius and the desired profile.Burr Grinding of Fillet Welds for Improved Fatigue Life
Note: The profile or geometry of the weld toe controls the fatigue performance of fabricated structures. These fabricated structures have attachments that are fillet welded to highly stressed members. Fatigue performance improvement can be achieved through alteration of the original toe profile by several post weld treatment options. This procedure describes a method of using a mechanical means in order to remove adverse profiles and adverse stress risers. This method creates a smooth transition from one component to the next component.
Table 15
Required Equipment    
Tool     Description    
Hand Held Grinder     High speed, pneumatic, rotary, pencil grinder - 20,000 rpm    
Compressed Air    
621 kPa (90 psi) minimum    
Tungsten Carbide Burr     The burr is conical shaped with an end diameter of approximately
10.0 mm (0.39 inch).    
Leather Welding Jacket        
Leather Gloves        
Safety Glasses        
Face Shield        
Radius Gauge        
Bridge Cam Gauge        
Illustration 149 g02001292
Pneumatic Rotary Pencil Grinder with Burr
The arrow points to the preferred burr shape.
Illustration 150 g02001298
Burr grinding the weld
The burr tip should be located over the weld toe. The axis of the tool should be maintained at approximately 45 degrees to the parent plate. The axis of the tool should be inclined at approximately 45 degrees to the direction of travel. Grinding should extend to a depth of 0.5 mm (0.02 inch) below the last visible traces of the weld toe resulting in minimum depth of 0.8 mm (0.03 inch) and maximum depth of 1.0 mm (0.04 inch). The