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Welding Glossary


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 * Scarf Joint ** - A form of a Butt Joint.


 * Seal Weld ** - Any weld designed primarily to provide a specific degree of tightness against leakage.


 * Seam Weld ** - A continuous weld made between or upon overlapping members, in which coalescence may start and occur on the faying surfaces, or may have proceeded from the surface of one member. The continuous weld may consist of a single weld bead or a series of overlapping spot welds.


 * Seam Welding ** - The making of seam welds.


 * Secondary Circuit ** - That portion of a welding machine which conducts the secondary current between the secondary terminals of the welding transformer and the electrodes, or electrode and work.


 * Selective Block Sequence ** - A block sequence in which successive blocks are completed in a certain order selected to create a predetermined stress pattern.


 * Semi-Automatic Arc Welding ** - Arc welding with equipment which controls only the filler metal feed. The advance of the welding is manually controlled. (2) **Semiautomatic Welding** - The equipment controls only the electrode wire feeding. The welding gun movement is controlled by hand.


 * Semi-Blind Joint ** - A joint in which one extremity of the joint is not visible.


 * Shielded Carbon Arc Welding (SCAW). ** A Carbon Arc Welding Process variation, which produces coalescence of metals by heating them with an electric arc between a carbon electrode and the work. Shielding is obtained from the combustion of a solid material fed into the arc or from a blanket of flux on the work or both. Pressure may or may not be used and filler metal may or may not be used.


 * Shielded Metal Arc Welding (SMAW) ** - An arc welding process, which produces coalescence of metals by heating them with an arc between a covered metal electrode, and the work. Shielding is obtained from decomposition of the electrode covering. Pressure is not used and filler metal is obtained from the electrode.


 * Shielding Gas ** - Protective gas used to prevent atmospheric contamination. (2) ** Shielding Gas ** – A gas used in MIG/GMAW/TIG/GMAW to prevent harmful contamination from atmospheric gases and vapors (See also Inert gas)


 * Short Circuiting Arc Welding ** - See Gas Metal Arc Welding-Short Circuit Arc (GMAW-S).


 * Short Circuiting Transfer (gas metal arc welding ** ). A type of metal transfer in which melted material from a consumable electrode is deposited during repeated short circuits.


 * Shrinkage Void ** - A shrinkage void is a cavity-type discontinuity normally formed by shrinkage during solidification.


 * Sieve Analysis ** - A method of determining particle size distribution, usually expressed as the weight percentage retained upon each of a series of standard screens of decreasing mesh size.

**Silica** - Millions of workers have been exposed to respirable crystalline silica in a variety of industries and occupations, including construction, sandblasting, and mining. Silicosis, an irreversible but preventable disease, is the illness most closely associated with occupational exposure to the material, which also is known as silica dust. Occupational exposures to respirable crystalline silica are associated with the development of silicosis, lung cancer, pulmonary tuberculosis, and airways diseases. These exposures may also be related to the development of autoimmune disorders, chronic renal disease, and other adverse health effects.

**Silicosis** - The pneumoconioses are a group of interstitial lung diseases caused by the inhalation of certain dusts and the lung tissue’s reaction to the dust. The principal cause of the pneumoconioses is work-place exposure; environmental exposures have rarely given rise to these diseases. The primary pneumoconioses are asbestosis, silicosis, and coal workers’ pneumoconiosis. As their names imply, they are caused by inhalation of asbestos fibres, silica dust, and coal mine dust. Typically, these three diseases take many years to develop and be manifested, although in some cases – silicosis, particularly – rapidly progressive forms can occur after only short periods of intense exposure. When severe, the diseases often lead to lung impairment, disability, and premature death. From a public health perspective, these conditions are entirely man-made, and can be avoided through appropriate dust control.


 * Single-Welded Joint ** - In arc and gas welding, any joint welded from one side only.


 * Single-Phase Circuit ** - An electrical circuit producing only one alternating cycle within a 360 - degree time span.


 * Size Of Weld **
 * ** Groove Weld ** . The joint penetration (depth of bevel plus the root penetration when specified). The size of a groove weld and its effective throat are one and the same.
 * ** Fillet Weld ** . For equal leg fillet welds, the leg lengths of the largest isosceles right triangle which can be inscribed within the fillet weld cross section. For unequal leg fillet welds, the leg lengths of the largest right triangle which can be inscribed within the fillet weld cross section.
 * ** Note ** : When one member makes an angle with the other member, greater that 105 degrees, the leg length (size) is of less significance than the effective 12 of 15 throat which is the controlling throat which is the controlling factor for the strength of a weld.
 * ** Flange Weld. ** The weld metal thickness measured at the root of the weld.


 * Skull ** - The un-melted residue from a liquated filler metal.


 * Slag Inclusion ** - Nonmetallic solid material entrapped in weld metal or between weld metal and base metal.


 * Slot Weld ** - A weld made in an elongated hole in one member of a lap or T-joint joining that member to that portion of the surface of the other member which is exposed through the hole. The hole may be open at one end and may be partially or completely filled with weld metal. (A fillet welded slot should not be construed as conforming to this definition).


 * Slugging ** - The act of adding a separate piece or pieces of material in a joint before or during welding that results in a welded joint not complying with design, drawing, or specification requirements.


 * Solidus ** - The highest temperature at which a metal or alloy is completely solid.


 * Soldering ** - A method of joining metal parts using a filler material (solder) that has a melting temperature below 450°C (842°F).


 * Spacer Strip ** - A metal strip or bar prepared for a Groove Weld, and inserted in the root of a joint to serve as a backing and to maintain root opening during welding. It can also bridge an exceptionally wide gap due to poor fit-up.


 * Spatter ** - In arc and gas welding, the metal particles expelled during welding and which do not form a part of the weld.


 * Spatter Loss ** - Metal lost due to spatter.


 * Spool ** - A type of filler metal package consisting of a continuous length of electrode wound on a cylinder (called the barrel), which is flanged at both ends. The flange extends below the inside diameter of the barrel and contains a spindle hole.


 * Spot Weld ** - A weld made between or upon overlapping members in which coalescence may start and occur on the faying surfaces or may proceed from the surface of one member. The weld cross section (plan view) is approximately circular. See also arc spot weld. (2) **Spot Welding** - Usually made on materials having some type of overlapping joint design. Can refer to resistance, MIG or TIG spot welding. Resistance spot welds are made from electrodes on both sides of the joint, while TIG and MIG spots are made from one side only.


 * Spray Transfer (arc welding) ** - A type of metal transfer in which molten filler metal is propelled axially across the arc in small droplets.


 * Square-Groove Weld ** - A type of groove weld.


 * Staggered Intermittent Fillet Welding ** - Two lines of intermittent fillet welding on a joint in which the fillet weld increments is one line are staggered with respect to those in the other line.


 * Standard Operating Procedure** (SOP) - SOP's provide students and employees with a reference to common safe operating practices and procedures. Students and new employees may use an SOP to answer questions without having to interrupt supervisors to ask how an operation is performed.


 * Stitch Welding ** - The use of intermittent welds to join two or more parts.


 * Stick Welding (SMAW or Shielded Metal Arc) ** - An arc welding process, which melts and joins metals by heating them with an arc, between a covered metal electrode and the work. Shielding gas is obtained from the electrode outer coating, often called flux. Filler metal is primarily obtained from the electrode core.


 * Straight Polarity ** - The arrangement of direct current arc welding leads in which the work is the positive pole and the electrode is the negative pole of the welding arc. A synonym for Direct Current Electrode Negative.


 * Stress Corrosion Cracking ** . Failure of metals by cracking under combined action of corrosion and stress, residual or applied. In brazing, the term applies to the cracking of stressed base metal due to the presence of a liquid filler metal.


 * Stress Relief Cracking ** - Intergranular cracking in the heat-affected zone of weld metal that occurs during the exposure of weldments to elevated temperatures during post-weld heat treatment or


 * Stringer Bead ** - A type of weld bead made without appreciable weaving motion. See also weave bead.


 * Submerged Arc Welding (SAW-S) ** - A submerged arc welding process variation in, which electric current is established between two (consumable) electrodes, which meet just above the surface of the work. The work is not in the electrical circuit. (2) ** Submerged Arc Welding (SAW) ** - A process by which metals are joined by an arc or arcs between a bare metal electrode or electrodes and the work. A granular, fusible material usually brought to the work from a flux hopper supplies shielding.


 * Substrate ** - Any base material to which a thermal sprayed coating or surfacing weld is applied.


 * Surface Preparation ** - The operations necessary to produce a desired or specified surface condition.


 * Surfacing ** -The deposition of filler metal (material) on a base metal (substrate) to obtain desired properties or dimensions. See also buttering, cladding, coating and hard facing. surfacing weld. A type of weld composed of one or more stringer or weave beads deposited on an unbroken surface to obtain desired properties or dimensions.

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