Shielded Metal Arc Welding (SMAW)

Comprehensive vocabulary flashcards covering Shielded Metal Arc Welding (SMAW) safety protocols, equipment setup, welding circuit components, electrode construction and classification, weld bead anatomy, and operational variables.

Shielded Metal Arc Welding (SMAW)

The most widely used arc welding process in the world, commonly known as 'stick' or manual arc welding, in which an electric arc is maintained between a covered consumable electrode and the base metal.

Thermal Plume

The rising column of hot gases and metal particles that sits directly above the weld pool and contains the highest concentration of toxic fumes.

Photokeratitis

A painful eye condition commonly called arc eye or welder's flash, caused by direct or reflected exposure to ultraviolet ($\text{UV}$) radiation emitted by the welding arc.

Arc Radiation

Emissions generated by the electric arc comprising intense visible light, ultraviolet ($\text{UV}$) radiation, and infrared ($\text{IR}$) radiation, which can burn unprotected skin and damage the eyes.

Electric Shock Prevention (SMAW)

Safety practices including keeping dry insulation between the body and the workpiece or ground, checking cables to ensure zero fraying, and never touching the electrode and workpiece simultaneously with bare skin.

Filter Lens Selection (SMAW)

The required optical shade density determined by electrode size and current; for example, an electrode size of $3/32\text{''}\text{ to }5/32\text{''}$ ($2.4\text{ to }4.0\text{ mm}$) at $60\text{ to }160\text{ A}$ requires an OSHA minimum shade of $8$ and an ANSI/AWS recommendation of $10$.

SMAW Welding Circuit

An electrical path where current travels from the arc welding power source through the electrode cable, into the electrode holder and electrode, across the arc, through the base metal to the workpiece clamp, and back along the workpiece lead.

SMAW Consumable Electrode

An electrode that melts during welding, composed of two parts: a central core rod that carries current and deposits filler metal, and an outer flux coating.

Core Rod (Metal Filler)

The solid inner metallic wire of an SMAW electrode that carries current to the arc and melts to become deposited weld metal.

Flux Coating

The outer chemical covering on an SMAW electrode that burns to produce shielding gas, can supply additional metal filler, and melts to form a protective slag layer.

Iron Powder Enrichment

High-deposition flux coatings packed heavily with iron powder compounds that melt alongside the core wire to increase total deposited weld metal by $30\%$ to $50\%$.

Slag

A lightweight layer formed by non-metallic flux components melting and floating to the top of the weld pool to shield it from atmospheric contamination, cooling into a glass-like shell that must be chipped away.

CLAMS

An acronym representing the five operator-controlled inputs in SMAW: Current, Length of arc, Angle of electrode, Manipulation, and Speed of travel.

Scratch Start

A technique for initiating an arc by striking and brushing the tip of the electrode against the base metal in a motion similar to striking a match.

Tap Start

A technique for striking an arc by bringing the electrode vertically down to tap against the workpiece and then immediately pulling it back to establish the correct arc length.

Work Angle

The angle between the electrode and the surface of the workpiece, measured perpendicular to the weld axis (typically $90^\circ$ on a flat butt joint).

Travel Angle (Lead Angle)

The angle between the electrode and a plane perpendicular to the weld axis along the line of travel, typically maintained between $20^\circ$ and $30^\circ$.

Arc Length

The distance between the tip of the electrode and the surface of the workpiece, normally maintained at approximately $1/8\text{''}$.

Travel Speed

The rate at which the electrode advances along the joint; excessive speed produces a narrow, ropey or convex bead, while insufficient speed creates a wide weld with excessive metal deposit.

Crater

A depression formed in the weld pool at the point where the arc is broken at the completion of a weld pass, which can cause cracking if not filled properly.

Back Stepping

A short pause or brief movement in the opposite direction of weld travel executed at the end of a pass to fill the crater and prevent weld cracking.

Bead Restart Technique

The procedure for continuing an interrupted bead: 1. strike the arc ahead of the crater, 2. move the electrode back to the crown of the crater, and 3. resume forward travel.

Fillet Weld Anatomy

The components of a fillet weld, consisting of the leg (weld size), toe, face, theoretical throat, actual throat, root, fusion zone (filler penetration), and work surface.

Groove Weld Anatomy

The components of a groove weld, including the reinforcement, weld size, toe, face, root, root penetration, work surface, and fusion zone.

Weld Toe

The junction where the face of the weld meets the surface of the base metal.

Weld Face

The exposed surface of a weld on the side from which welding was performed.

Weld Root

The point where the back or bottom of a weld intersects the base metal surfaces.

Weld Reinforcement

Weld metal in excess of the amount required to fill a groove, extending above the surface plane of the base metal.

Root Penetration

The depth that a groove weld extends into the root of a joint below the original work surface.

Fusion Zone

The area of base metal melted and blended with filler metal, as observed in a cross section of the weld joint.

Leg (Weld Size)

The distance measured from the joint root to the toe of a fillet weld, which establishes the designated weld size.

Theoretical Throat vs. Actual Throat

Theoretical throat is the distance from the joint root perpendicular to the hypotenuse of the largest triangle inscribed within the fillet weld; actual throat is the shortest distance from the root to the face.

AWS Classification: 'E' Prefix

The initial letter in the AWS electrode specification indicating that the consumable is an electric arc welding electrode.

AWS Classification: First Two Digits (e.g., '70')

The digits indicating the minimum tensile strength of the deposited weld metal measured in kilopounds per square inch ($\text{ksi}$), where $70$ designates $70\text{,}000\text{ psi}$.

AWS Classification: Third Digit (e.g., '1' or '2')

The digit indicating permissible welding positions, where '$1$' denotes all positions and '$2$' denotes flat and horizontal positions only.

AWS Classification: Final Digit

The digit that specifies the coating type, electrical current compatibility, and polarity (such as AC, DCEP, or DCEN).