Shielded Metal Arc Welding(SMAW)

  • Manual arc welding

–Heat for welding generated by electric arc established between flux-covered consumable metal rod (electrode) and work

  • Called stick electrode welding
  • Combustion and decomposition of electrode creases gaseous shield

–Protects electrode tip, weld puddle, arc, and highly heated work from atmospheric contamination

  • Additional shielding provided by covering of molten slag (flux)

SMAW advantages

  • Equipment less complex, more portable and less costly
  • Can be done indoors or outdoors, in any location and any position
  • Electrodes available to match properties and strength of most base metals

–Not used for welding softer metals

–Not as efficient in deposition

SMAW operating principles

  • Sets up electric circuit

–Includes welding machine, work, electric cables, electrode holder and electrodes, and a work clamp

  • Heat of electric arc brings work to be welded
    and consumable electrode to molten state

–Heat intense: as high at 9,000ºF at center

Welding process:

  • Electric arc started by striking work with electrode
  • Heat of arc melts electrode and surface of base metal
  • Tiny globules of molten metal form on tip of electrode and transferred by arc into molten pool on work surface
  • After weld started, arc moved along work