1. Shielded Metal Arc Welding (SMAW)

3. What is SMAW? SMAW often referred to as “stick” or “manual” welding.
Metal rod covered with flux that provides the shielding to protect the weld.
Uses constant current power sources.
Most widely used form of welding in the world.
Used for fabrication of ships, pressure vessels, tanks, automobiles, and appliances.

4. SMAW Safety Eye Protection Proper Work Clothing
Safety Glasses, welding helmet
Proper Work Clothing
Jacket, Coveralls, gloves
Electrical equipment hazard
Frayed connections, water, protecting yourself from becoming part of the circuit

5. SMAW Overview
SMAW utilizes an arc welding machine to join 2 pieces of metal together.
Electric Arc established between flux covered electrode and base metal.
Heat from the arc melts metal and mixes with deposits of electrode.

7. SMAW Electrical Principles
When welding SMAW, an electrical circuit is created.
Electrical circuit; path taken by electrical current flowing from one terminal of the machine, through a conductor to the other terminal.
Current; amount of electron flow through an electrical circuit

8. Conductor; any material through which electricity flows easily.
Resistance; opposition of the material in a conductor to the passage of electrical current causing heat.
Heat is caused in SMAW by an air/gas gap between the electrode and base metal

9. SMAW Electrical Terms Revisited
Ampere (amp, or A): Unit of measuring electricity/ electron flow.
Amperage: Quantity of electricity (amps) measured.
Voltage: Electrical pressure that causes current to flow

10. Current Flow
Alternating Current- electrical current where electrons flow in both positive and negative values
Direct Current- electrical current that flows in only one direction. Polarity refers to the direction in which electricity is flowing.
DCEP; Direct Current Electrode Positive
DCEN; Direct Current Electrode Negative

11. SMAW Equipment Power Supply
Must maintain constant current with only a light change in voltage
Varying voltage and current will result in an uneven arc that creates spatter and uneven welds
Multiple types of power supplies (generators, transformers, rectifiers, inverters)

13. SMAW Equipment
Welding Leads: conduct current to and from the work piece.
Lead with the electrode holder attached is called the electrode lead
Lead with the workpiece connector attached is called the workpiece lead. Commonly but incorrectly referred to as the ground clamp.

14. SMAW Equipment Electrode Holders
Handle-like tool that holds the electrode during welding.
Receives amperage and directs it through the electrode to form an arc.
Should be well insulated and free from defect.

15. SMAW Equipment Work Piece Connection
Must be connected to work piece or bench to complete electrical circuit.
Connections are made to be removable for easy mobility

16. SMAW Equipment Electrodes
Consists of internal metal core, and an outer coating called flux.
Metal core melts into molten base metal.
Flux is turned into gas shield as it burns away.
Several types and sizes of electrodes.

17. SMAW Equipment Welding Helmet
Used to filter the intense UV light produced from the arc welding process.
Needs to be at least a #10 shade
Auto shade helmets can be set to a particular shade number and don’t need to manually change the filter lens

18. SMAW Equipment Clothing
Pants and Jackets need to be thick to help protect skin and body from the heat and UV light produced from welding
Gloves need to be thick and insulated
Arms and legs must be covered at all times while using SMAW

19. Electrodes
Electrodes are coated metal wire with the same composition as the base metal to be welded.
5 main classification groups
Mild steel
High carbon
Special alloy steel
Cast iron
Nonferrous

20. Electrodes Flux coating contains various substances
Components of flux serve multiple purposes
Cleansing and deoxidizing agent in molten crater
Release Carbon Dioxide to protect molten metal
Form slag over deposited weld bead
Provide easier arc starting, stabilization, reduce spatter
Improve weld penetration

21. Electrodes Electrode Identification-AWS standardized numbering system
Example= E6013
What does this number mean?

22. E6013 E= Electric Arc Welding
60 (first 2 digits)=Tensile strength in 1000/lbs
1 (third digit)= Welding Position
3 (fourth digit)= Type of flux/ welding current