- Shielded metal arc welding (SMAW) is one of the most commonly used welding processes, accounting for approximately 50% of welding in industry. - SMAW uses a consumable electrode covered in flux that generates an electric arc to both melt the base metal and provide shielding from contamination. - Constant current welding machines, which maintain a constant current output regardless of changes in arc length, are best suited for SMAW and allow welders to control heat input.

1. S hielded Metal Arc Welding Principles Chapter 11

5. SMAW American Welding Society Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

10. SMAW Operating Principle American Welding Society Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

16. Typical Output Slopes Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

22. Constant Current Output Slope Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Some jobs require steep volt-ampere curve Other jobs use less steep volt-ampere curve

27. Motor-Generator Welding Machine Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hobart Brothers Co. Sturdy steel lifting eye Large voltmeter Calibrated dial for easy, fine adjustment of heat and relation between voltage and current Outer wheel and dial for selecting desired welding range Stop button

28. Motor-Generator Welding Machine Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hobart Brothers Co. Ground cable connector Optional steel guard Heavy-duty ball bearings Pressed steel bearing cap Arc welded copper squirrel cage rotor Motor stator Heavy steel fan

29. Motor-Generator Welding Machine Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hobart Brothers Co. Steel frame Fourpole "Multi-Range" generator Large commutator Heavy-duty metallic graphite brushes Heavy-duty ball bearings Pressed steel bearing cap Arc welded steel frame

30. Motor-Generator Welding Machine Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hobart Brothers Co. Removable steel covers Heavy-duty single unit steel shaft Polarity switch Welding cable connector Large ammeter Steel turret top with removable cover

31. Motor Generator Welding Machine for SMAW Variable voltage control Instruction on the Name-plate Polarity switch Current control Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Toggle switch Constant voltage The Lincoln Co.

32. External Construction of d.c. Motor Generator Welding Machine Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Lincoln Electric Co.

33. Internal Construction of a D.C. Motor Generator Welding Machine Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Lincoln Electric Co.

44. Engine Driven Generator Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Capable of SMAW, GTAW, SMAW, FCAW and PAC. Miller Electric Mfg. Co. Miller Electric Mfg. Co.

50. A.C.-D.C. Transformer-Rectifier Welding Machines Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. A 300 amp a.c.-d.c. GTAW/SMAW machine. Portable SMAW/GTAW welding machine A 300 amp model shown in use The Lincoln Electric Co. The Lincoln Electric Co. Miller Electric Mfg. Co.

71. Spring Type Electrode Holder Lenco dba NLC. Inc. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

72. Short-stub Electrode Holder Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cable connections Special extruded copper-alloy body High welding current conductance One-ton pressure contact Lifeguard insulation Entirely insulated Bernard Welding Equipment Co. Holds electrodes burned to very short stub. Twist-type locking device permits electrode- gripping power in excess of 2,000 pounds.

73. Angle-head Electrode Holder Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Jackson Products Co. Available in sizes of 400 and 600 amperes and takes electrodes from 1/16 through 5/16 inch in diameter. Shorter and lighter than other holders of comparable capacity.

76. Twin Carbon Electrode Holder Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Lincoln Electric Co. Two leads are required because the arc is created between the two electrodes. Metal shield to protect welder's hand from intense heat. Larger than the metal electrode holder Holder is water cooled

78. Atomic-Hydrogen Electrode Holder Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. General Electric Co.

88. Protective Clothing Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.