Introduction to Welding Terminology
1. Alternating Current (AC)- is an electric current which periodically reverses direction
2. Amperage- the strength of an electric current in amperes
3. Arc Blow- is the deflection of welding filler material within an electric arc deposit by a buildup of magnetic
force surrounding the weld pool
4. Arc Length- Arc length is literally the length of the arc of a portion of a circle. This arc is a part of the total
circumference of a circle. This length is measured as a linear distance.
5. Backhand (Drag)- The backhand method means the torch is positioned so that the wire is feeding opposite
to the direction of arc travel
6. Base Metal- a common metal that is not considered precious, such as copper, tin, or zinc.
7. Bevel Angle- an instrument consisting of two rules or arms jointed together and opening to any angle for
drawing angles or adjusting surfaces to be cut at an angle
8. Butt Joint- a joint formed by two surfaces abutting at right angles.
9. Code- To put it simply, a coded welder is someone who has completed a Welder Approval Test in a
specific welding configuration. Each method is specific to a certain job in hand, some codes are more
general and some are very specific.
10. Complete Joint Penetration (CJP)- The Complete Joint Penetration (CJP) groove weld is a groove weld that
extends completely through the thickness of components joined.
11. Concavity- A weld that drops under the intended perpendicular plane.
12. Conductor- An electrical conductor is a substance in which electrical charge carriers, usually electrons,
move easily from atom to atom with the application of voltage
13. Constant Current Power Source- A constant current source is a power source which provides a constant
current to a load, even despite changes and variance in load resistance
Introduction to Welding Terminology
14. Coupons- Coupons are just a fancy name for the steel that you practice welding on." In this case, "coupon"
means a rectangular piece of metal of required thickness and size (length and width) prepared for
the welding which will be done on it.
15. Convexity- Convexity is a measure of the curvature, or the degree of the curve, in the relationship between
bond prices and bond yields.
16. Crater- A crater pipe forms during the final solidified weld pool and is often associated with some gas
porosity. This imperfection results from shrinkage on weld pool solidification.
17. Current- Also called amperage. The amount of electricity flowing through a point in a conductor every
second.
18. Defect- Welding Defects can be defined as the irregularities formed in the given weld metal due to
wrong welding process or incorrect welding patterns
19. Deoxidizers- Deoxidizers act as scavengers that combine with oxygen and then, as the weld metal cools,
they diffuse with the oxygen to the surface of the weld
20. Deposition Rate- The deposition rate is the rate that weld metal can be deposited by a given electrode
or welding wire, expressed in pounds per hour
21. Depth of Fusion- penetration, or properly termed depth of fusion, is defined by AWS as, “The distance
that fusion extends into the base metal or previous pass from the surface melted during welding”
22. Direct Current- Direct current (DC) is electricity flowing in a constant direction and/or possessing a voltage
with constant polarity, either positive or negative
23. DCEN- Direct Current Electrode Negative (DCEN) The direction of current flow through a welding circuit
when the electrode lead is connected to the negative terminal of the power source and the work is
connected to the positive terminal. Sometimes referred to as straight polarity.
24. DCEP- Direct current electrode positive (DCEP) is what we used to call reverse polarity.
Introduction to Welding Terminology
25. Discontinuity- Technically, a welding discontinuity is the lack of a mechanical, physical or metallurgical
harmony in the weld. This could be manifested in terms of. Varied porosity. Incomplete fusion or joint
penetration.
26. Distortion- Distortion in a weld results from the expansion and contraction of the weld metal and adjacent
base metal during the heating and cooling cycle of the welding process
27. Drag lines- a line used in or for dragging.
28. Ductility- Ductility is a measure of a metal's ability to withstand tensile stress—any force that pulls the two
ends of an object away from each other.
29. Duty Cycle- Duty cycle is a welding equipment specification which defines the number of minutes, within a
10 minute period, during which a given welder can safely produce a particular welding current.
30. Effective Throat- Effective Throat – The minimum distance minus any reinforcement between
the weld root and the face of a fillet weld.
31. Elasticity- The elasticity of a metal refers to the rate at which a given metal sample is able to distort its size
and shape under a range of stress and strain forces and other externally varying factors.
32. Elongation- A mechanical property of metal that is the degree to which a material may be bent, stretched,
or compressed before it ruptures. It is a point between tensile strength and yield strength and is expressed
as a percentage of the original length.
33. Fatigue Strength- An increase in thickness of a base material decreases the fatigue strength when a crack
propagates from the toe of a welded joint.
34. Fill Pass- Fill – Also referred to as a fill pass, it is the amount of weld bead necessary to fill the weld joint.
35. Filler Metal- A filler metal is a metal added in the making of a joint through welding, brazing, or soldering.
36. Fillet Weld- Fillet welding refers to the process of joining two pieces of metal together whether they be
perpendicular or at an angle. These welds are commonly referred to as Tee joints which are two pieces of
Introduction to Welding Terminology
metal perpendicular to each other or Lap joints which are two pieces of metal that overlap and
are welded at the edges.
37. Fillet Weld Leg- The face of the weld is the outer visual or hypotenuse that you see when looking at a fillet
weld. The legs are the opposite and adjacent sides to the triangular fillet weld. The leg length is usually
designated as the size of the weld.
38. Fire Watch- Fire watch personnel maintain surveillance of areas where hot work -- welding or cutting with
torches -- has occurred.
39. Flashback- A flashback is when fuel gas is ignited or burns back behind your torch tip in oxyfuel cutting
or welding
40. Flow rate- A gas flow rate is the volume of gas that passes a particular point in a particular period of time.
41. Forehand (push)- forehand welding. Welding in which the flame is directed against the base metal ahead
of the weld and is moved in the direction of welding
42. Frequency- Radio frequency welding or (high frequency welding) is the process of bonding together
materials through the use of electromagnetic energy.
43. Fusion- Fusion welding is a generic term for welding processes that rely on melting to join materials of
similar compositions and melting points.
44. Fusion Face- Root penetration is the distance into the root face, or beyond the bottom of the bevel,
the weld melted or fused. Depth of fusion is measured perpendicular (or normal) to the
bevel face (or fusion face after the weld is completed).
45. Groove Angle- Groove Angle. The included angle between the groove faces of a weld groove.
46. Hardness- The hardness is determined by measuring the depth of indenter penetration or by measuring
the size of the impression left by an indenter.
Introduction to Welding Terminology
47. Hazard Communication Standard (HCS)- According to OSHA, the purpose of the Hazard Communication
Standard (HCS) is “to ensure that the hazards of all chemicals produced or imported are evaluated and
details regarding their hazards are transmitted to employers and employees."
48. Hazardous Material Identification System (HMIS)- The Hazardous Materials Identification System (HMIS) is
a numerical hazard rating that incorporates the use of labels with color developed by the American
Coatings Association as a compliance aid for the OSHA Hazard Communication (HazCom) Standard.
49. Heat Affected Zone (HAZ)- The Heat-Affected Zone (HAZ) refers to a non-melted area of metal that has
experienced changes in its material properties as a result of exposure to high temperatures. The
alterations in material properties are usually a result of welding or high-heat cutting procedures.
50. Hot Pass- A hot pass is a term used in stove-pipe welding, when the bead is complete it is given a quick
clean up with a grinder then the hot pass follows, it burns out the slag that is trapped at the junction
between the bead and the pipe wall, the slag is often called wagon tracks.
51. Hot Work Permit- Hot work is any work that involves burning, welding, cutting, brazing, soldering, grinding,
using fire- or spark-producing tools, or other work that produces a source of ignition.
52. Impact Strength- Impact toughness is the ability of a weld to permanently deform while absorbing energy
before fracturing, specifically when stress is applied rapidly—typically, in under one second. In simpler
terms, it's how much rapid-impact energy a weld can take before it cracks.
53. Inclusion- Linear inclusions occur when there is slag or flux in the weld. Slag forms from the use of a flux,
which is why this type of defect usually occurs in welding processes that use flux, such as shielded metal
arc welding, flux-cored arc welding, and submerged arc welding, but it can also occur in gas metal
arc welding.
54. Inductance- Inductance is the property in an electrical circuit that slows down the rate of current rise, Fig.
2. The current travelling through an inductance coil creates a magnetic field. This magnetic field creates a
current in the welding circuit that is in opposition to the welding current.
Introduction to Welding Terminology
55. Inert gas- Shielding gases fall into two categories—inert or semi-inert. Only two of the noble gases, helium
and argon, are cost effective enough to be used in welding. These inert gases are used in gas tungsten
arc welding, and also in gas metal arc welding for the welding of non-ferrous metals.
56. Insulator- An electrical insulator is a material whose internal electric charges do not flow freely; very little
electric current will flow through it under the influence of an electric field.
57. Intermittent Welds- The pitch is a measurement from midpoint to midpoint of the intermittent
welds. Intermittent welding is used when either a continuous weld is not necessary, or when a continuous
weld threatens the joint by warping.
58. Ionization Potential- The low ionization potential of argon creates an excellent current path and superior
arc stability. Argon produces a constricted arc column at a high current density which causes the
arc energy to be concentrated in a small area.
59. Joint- A welding joint is a point or edge where two or more pieces of metal or plastic are joined together.
60. Kerf- Kerf is defined as the width of material that is removed by a cutting process.
61. Kindling Temperature- Before you can start cutting the steel, it has to be heated up to its kindling
temperature, about 1800°F. At this temperature, the steel readily reacts with oxygen. The heat is provided
by the preheat flames from an oxy-fuel torch.
62. Lap Joint- Lap Joint. Lap welding joints are used most often to joint two pieces with differing thicknesses
together.
63. Malleability- Malleability is a physical property of metals that defines the ability to be hammered, pressed
or rolled into thin sheets without breaking. In other words, it is the property of a metal to deform under
compression onto a different form.
64. Material Safety Data Sheet (MSDS)- A Material Safety Data Sheet (MSDS) is designed to provide both
workers and emergency personnel with the proper procedures for handling or working with a particular
substance.
Introduction to Welding Terminology
65. Mechanical Properties- Heat can alter the mechanical properties of any metal like making a soft metal
hard and then soft again. Fusing metals with compatible mechanical properties is an
important welding skill because it can affect the product.
66. Neutral Flame- The neutral flame has a one-to-one ratio of acetylene and oxygen. It obtains additional
oxygen from the air and provides complete combustion. It is generally preferred for welding.
67. Occupational Safety- and Health Administration (OSHA)- The Occupational Safety and Health
Administration (OSHA) has developed rules and regulations for workplace safety for virtually all industries
68. Overlap- Overlap is defined as a protrusion of weld metal beyond the weld toe, or weld root.
69. Oxidizing Flame- In various burners, the oxidizing flame is the flame produced with an excessive amount of
oxygen.
70. Peening- Peening is used to help a weld joint stretch as it cools by relieving internal stresses.
71. Personal Protective Equipment (PPE)- Protective Clothing includes welding gloves, coat, sleeves, and
leg protection. Personnel exposed to the hazards created by welding, cutting, or brazing operations shall
be protected by personal protective equipment in accordance with OSHA standards, Subpart I, Personal
Protective Equipment, paragraph 1910.132.
72. Plasma- A plasma is a hot ionized gas consisting of approximately equal numbers of positively charged ions
and negatively charged electrons.
73. Plasticity- the quality of being easily shaped or molded.
74. Polarity- Polarity. ... With direct current (DC) the welding circuit can either be straight, or reverse polarity.
When the machine is set for straight polarity, the current flows from the electrode to the weld surface and
creates considerable heat in the metal.
75. Porosity- Porosity is caused by the absorption of nitrogen, oxygen and hydrogen in the molten weld pool
which is then released on solidification to become trapped in the weld metal.
Introduction to Welding Terminology
76. Procedure Qualification Record (PQR)- The AWS defines welding PQR as a record of welding variables used
to produce an acceptable test weldment and the results of tests conducted on the weldment
to qualify a Welding Procedure Specification.
77. Quenching- Quenching is a rapid way of bringing metal back to room temperature after heat treatment to
prevent the cooling process from dramatically changing the metal's microstructure.
78. Rectification- A rectifier is an electrical device that converts alternating current (AC), which periodically
reverses direction, to direct current (DC), which flows in only one direction.
79. Reinforcement- reinforcement of weld, Weld metal that extends beyond the surface or plane of
the weld joint.
80. Residual Stress- Residual stress in welding. ... Residual stress in welding is mainly the result of thermal
expansion, which in basic terms means that materials expand or contract with temperature.
81. Resistance - Resistance welding is the joining of metals by applying pressure and passing current for a
length of time through the metal area which is to be joined.
82. Slag- Welding slag is a form of slag, or vitreous material produced as a byproduct of some arc welding
processes, most specifically shielded metal arc welding, submerged arc welding, and flux-cored arc
welding.
83. Spatter- A very common occurrence in gas metal arc welding (GMAW) is the creation of what welders call
“spatter,” which is essentially droplets of molten material that are generated at or near
the welding arc. Spatter is generally regarded as a nuisance and is a critical factor to consider when
developing an application
84. Specifications- an act of describing or identifying something precisely or of stating a precise requirement.
85. Standard- a level of quality or attainment.
86. Tack weld- Tack welding is a major part of welding which are used as a temporary means to hold the
components in the proper location, alignment, and distance apart, while welding. ... The tack is a very
Introduction to Welding Terminology
rapid quench application and a brittle, crack sensitive micro structure results usually at the root of
the weld.
87. Tensile Strength- Ultimate tensile strength, often shortened to tensile strength, ultimate strength, or Ftu
within equations, is the capacity of a material or structure to withstand loads tending to elongate, as
opposed to compressive strength, which withstands loads tending to reduce size.
88. Theoretical Throat- The distance from the beginning of the joint root perpendicular to the hypotenuse of
the largest right triangle that can be inscribed within the cross section of a fillet weld.
89. Travel angle- Travel angle is defined as the angle relative to the gun in a perpendicular position. Normal
welding conditions in all positions call for a travel angle of 5 to 15 degrees
90. Travel Speed- In addition, a certain range is required to maintain arc stability at any given welding current
level. ARC TRAVEL SPEED The arc travel speed is the linear rate that the arc moves along the workpiece.
91. Undercut- Undercutting is a groove or crater that occurs near the toe of the weld. When this weld flaw
occurs, the weld metal fails to fill in that grooved area, resulting in a weak weld that is prone to cracking
along the toes.
92. Under fill- while underfill according to A3.0 is A Grove Weld condition in which the weld root or face
surface is below the adjacent surface of the base metal and it gives a couple of figures to clarify.
93. Voltage- an electromotive force or potential difference expressed in volts.
94. Wattage- a measure of electrical power expressed in watts.
95. Welder Qualification Test Record (WQTR)- The AWS defines welding PQR as a record of welding variables
used to produce an acceptable test weldment and the results of tests conducted on the weldment
to qualify a Welding Procedure Specification. ... ASME also defines welding PQR as a record of
variables recorded during the welding of the test coupon.
96. Weld Face- Weld Face. The exposed surface of a weld on the side from which welding was done.
Introduction to Welding Terminology
97. Weld Toe- The toes of the weld are essentially the edges or the points of the hypotenuse. The face of
the weld is the outer visual or hypotenuse that you see when looking at a fillet weld. The legs are the
opposite and adjacent sides to the triangular fillet weld.
98. Weld Root- The weld root is the point at which the back of a weld intersects with the base metal surfaces.
It determines the weld penetration and fusion to form a rigid joint. It is made by the first root pass and
supported by other passes.
99. Welding Parameters- The four important parameters are the welding current, wire electrode
extension, welding voltage and arc travel speed. These parameters will affect the weld characteristics to a
great extent.
100.
Weld Pitch- The pitch is a measurement from midpoint to midpoint of the intermittent welds.
101.
Welding Procedure Specification(WPS)- A Welding Procedure Specification is the formal written
document describing welding procedures, which provides direction to the welder or welding operators for
making sound and quality production welds as per the code requirements.
102.
Weld Pool- Weld pool commonly refers to the dime-sized workable portion of a weld where the base
metal has reached its melting point and is ready to be infused with filler material. The weld pool is central
to the success of the welding process.
103.
Work Angle- Work angle is the angle from the horizontal measured at right angles to the direction of
welding
104.
Work Lead- Welding Work Lead Connections. In arc welding, an arc is established from the electrode to
the workpiece. To do this, a smooth flow of electricity needs to complete the electrical circuit, hence the
need for good electrical connections.
105. Yield Strength- The amount of
stress a material can withstand before it begins to deform plastically.
Introduction to Welding Terminology