ENGINE AR-PRIMARY 3131224 - Caterpillar

The four types of welds commonly used in service work are the bead, the groove, the fillet and the plug (Figure 37). The bead weld is a weld deposited in an unbroken string on a surface. The groove weld is a weld made in the space between two surfaces to be joined. The fillet weld is a weld of approximately triangular cross section that is used to join the two surfaces at an angle. The plug weld is a weld made through a plate to join it to another surface.
Figure 37 - Four types of welds and four joint configurations are used.Four types of joints are commonly employed in this type of welding: the lap joint, the T joint, the corner joint and the butt joint. (Figure 37). These joints can be combined with variations in groove configuration to give the common service welding joints shown in Figure 38.
Figure 38 - Joints can be combined with groove styles for many welds.Welding Symbols
Welding symbols are commonly understood by all welders. Basic weld symbols and supplementary symbols are shown in Figure 39. The weld symbol indicates the type of weld desired. A complete welding symbol, however, indicates the location, size and finish of the weld and gives other specifications and information.
Figure 39 - Basic and Supplementary Weld SymbolsThe eight elements of the welding symbol are: 1) the reference line, 2) the arrow, 3) the basic weld symbols, 4) the weld size, 5) the supplementary symbols, 6) the finish symbols, 7) the tail, and 8) the specification. A typical welding symbol is shown in Figure 40. A weld symbol placed below the reference line goes on the other side of the joint. A summary of standard welding symbols published by the American Welding Society is shown on Page 6. Refer also to Sections I through VIII of the AWS Standard Welding Symbols Code.
Figure 40 - The welding symbol gives location, size and finish of weld.Types of Electrodes
Electrodes used in arc welding can be classified according to operating characteristics, type of coating and characteristics of deposited metal. AWS specifications group electrodes in series (E45 Series, E60 Series, etc.) according to the minimum tensile strength of the deposited metal. The deposited metal from E80 Series electrodes, for example, has a minimum tensile strength of 80,000 psi in stress relieved condition. Each series is further subdivided according to welding position, coating composition and welding current. These are indicated by the last two digits in the classification number.
Figure 41 - Electrodes formerly were marked according to a AWS color code.Chart B - Electrode Coatings
Figure 42a - American Welding Society Basic/Typical Welding Symbols Chart
Figure 42b - American Welding Society Basic/Typical Welding Symbols Chart
Figure 43 - Welding Position
Figure 44 - Seven basic groove welds
Figure 45 - Some Typical Weld Joints
Figure 46