1. INTRODUCTION TO ARC WELDING (SMAW)

2. Terms & Definitions
Welding - Joining of two or more pieces of metal together by the fusion process
NOTE: In arc welding, heat is produced by the electric arc created.
SMAW - Shielded Metal Arc Welding
Electrode - Metal rod which conducts a current from the electrode holder to the base metal
Base Metal - Metal to be welded

3. Continued Bead Weld - Made by one pass of the electrode
Bevel – Type of edge preparation containing an angle
Butt Joint - Weld located between the two edges of metal.
Crater - Depression at the end of a weld

4. Safety precautions in SMAW welding
Never look at the arc with the naked eye.
Use a welding hood that is in good condition and has a #12 shade.
Wear suitable clothing to protect all parts of the body. (PPE) personal protective equipment
Long sleeved shirt
Leather gloves
Collar buttoned

5. Continued
Cuffs turned down
High topped shoes or boots
Do not strike an arc or weld until you are sure those in the vicinity have protective equipment or will look in the other direction.
(Note) Yell “cover” before striking an arc.

6. Continued Do not weld around combustible or flammable materials.
Do not pick up hot metal with the hands.
(NOTE) Use a pair of pliers
Do not weld in confined places without ventilation

7. Continued
Always turn off main switch or disconnect plug when checking over a welder.
Do not leave electrode holder on the welding table or in contact with grounded metal.
Do not use worn or frayed cables.

8. Continued Stand on dry footing when welding.
Keep area around welder clean.
Keep tools and metals in proper location.

9. Common SMAW Tools Welder Electrode Holder Ground clamp
Shield or helmet
Gloves
Chipping hammer
Safety goggles or glasses
Wire brush
Electrodes

10. Types of Electrodes Mild Steel High Carbon Steel Hard Surfacing
Alloys – special purpose

11. Electrode Characteristics

12. Electrode Characteristics continued

13. Common Sizes of Electrodes
1/8”
5/32”
Sizes of electrodes range from 1/16” to 3/8”.
Electrode size is determined by the diameter of the wire core.

14. E70XX-H4R AWS Classification 1 = All Position, 2 = Flat & Horizontal
Electrode
Tensile in Ksi
Welding Position:
1 = All Position, 2 = Flat & Horizontal
Type of Current and Coating
*Hydrogen:
H4 = Less than 4ml/100g weld metal, H8 = Less than 8ml/100g Weld Metal
or H16 = Less than 16ml/100g weld metal
*Meets Requirements of Absorbed Moisture Test
*Optional Designators 9

15. Electrode Coating Functions
To Provide Deoxidizers
To Produce Shielding Gases
To Produce a Slag Covering
To Provide Mechanical and Physical Properties
To Increase Deposit Rates 8

16. Effects of Raising & Lowering Current
Raising current
Produces more heat
Lowering current
Produces less heat
(Note: On thicker metals more heat is necessary in order to get penetration of the weld.)

17. Methods of Establishing an Arc
Scratching
Similar to striking a match
Tapping
Straight down and up

18. Characteristics of Proper Arc Length
End of electrode is the same distance from the base metal as the diameter of electrode.
1/8” electrode = arc length 1/8”
Correct arc length makes a steady hum of the welder.
Correct arc length makes a “frying” sound at the arc
Like bacon frying in a pan

19. Parts of the welding process
Electrode
Wire core
Coating (flux)
Arc
Gaseous shield
Weld
Slag

20. Parts Continued Heat lines Base metal Penetration Crater
15 – 30 degree angle
Direction of travel

21. Principles of the SMAW Process

22. Kinds of Welds
Fillet
Groove
Bead

23. Fillet Weld

24. Groove Welds

25. Continued

26. Types of Weld Joints Butt Joint Lap Joint Tee Joint Corner Joint
Edge Joint

27. Square Butt Joint

28. Tee Joints A- plain tee B- single beveled C- double beveled
D- single J
E- double J

29. Lap Joints A- single lap joint, one weld.
B- single lap joint, two welds.
C- offset lap joint.

30. Corner Joints

31. Edge Joints

32. Welding Positions Flat Horizontal Vertical Overhead 1F & 1G 2F & 2G

33. Weld Positions

34. Reason for Poor Welds Machine adjustment too hot or too cold
Electrode size too large or too small
Improper movement of electrode
Improper angle of holding electrode
Improper base metal preparation
Arc length too long or too short