Welding Glossary S

Safety cap A forged steel cap that should be screwed over the cylinder valve to protect it when the cylinder is stored or moved.
Safety disc A mechanical safety device for pressure vessels designed to release pressure at a predetermined value.Also called a safety valve.
Sagging The sinking or downward curving of metal (as in a welding pool), due to gravity.
Secondary circuit In a welding machine transformer, the electrical circuit and winding connected to the electrodes.
Self shielding electrode An electrode that produces its own shielding gas and does not require additional shielding gas.
Semiautomatic Welding In this welding process, the equipment controls the electrode wire feeding while the gun movement is controlled by hand.
Sequence The order in which operations or events take place.
Servomotor A small electric motor capable of precisely controlled movement.
Sharpie Tungsten Grinder The O.G. hand-held tungsten electrode grinder that delivers crisp arc starts and gives TIG welders better control of the weld puddle.  A Sharpie tungsten grinder the easiest way to greatly improve your TIG welding.
Shielding Gas Gas used to prevent contamination of the welding puddle.
Shielding Gas FLow Tester Device used to verify actual gas flow rate at the welding torch. Accurate shield gas flow rates improve weld quality and consistency, and lower welding costs.
Short circuit In the short circuiting transfer process, the condition that occurs when the electrode touches the base metal, causing metal from the electrode to enter the weld.
Short circuiting transfer A gas metal arc process that uses relatively low voltage.The arc is constantly interrupted and restarted as the molten electrode shorts out against the base metal.
Shoulder joint One of several axes (straight lines about which rotation can take place) on a typical robot.
SI Metric system Systeme Internationale- A measuring system used in most countries.It uses such units as millimeters, kilograms, liters, newtons, and pascals.
Side bend A test performed by bending a weld sample to the side toward the thickness of the metal.The side bend is used on thick material.
Single stage regulator A regulator that reduces cylinder pressure to working pressure in one stage (step).
Single Phase Circuit Electrical circuit which produces only one alternating cycle within a 360 degree span of time.
Sketches Simple drawings of parts made without drawing tools.
Skull The unmelted residue from a liquated filler metal.
Slag The hard, brittle metal that covers a finished shielded metal arc, flux cored, and submerged arc welding beads; metal oxides and other materials that form on the underside of an arc cut.
Slag inclusions Nonfused, nonmetallic substances in the weld metal.
Slope The downward curve of the volt-ampere diagram for an arc welding machine.
Slope adjustment Changing the slope of the volt-ampere curve by decreasing the maximum short circuit current.This reduces spatter during short circuiting transfer.
Solidus The highest temperature at which a metal or alloy is completely solid.
Spatter The particles blown away from the welding arc which do not become part of the finished weld.
Slot weld A weld similar to a plug weld, but made through an elongated (rather than round) hole.
Socket connection Preformed fitting soldered in place to connect lengths of thin walled tubing.
Solid state welding A group of welding processes that weld metals at temperatures below the melting point of the base metal, without the addition of filler metal.Examples are friction, explosion, and ultrasonic welding.
Solidify To become solid or hard.
Solidus The temperature at which the metal or alloy begins to melt.The liquidus is the temperature at which metal becomes completely liquid.
Spark igniter A device that creates a spark to ignite the oxyfuelgas torch flame.
Spatter The scattering of molten metal droplets over the surface near an arc weld.
Speed welding tip A tip for a welding torch that allows one-hand welding of plastics.
Spool The drum, mounted on a wire drive mechanism, that contains the electrode wire for MIG (GMAW) welding.
Spot Welding Can refer to MIG or TIG spot welding, this process usually is used on materials which have some overlapping joint design. Welds are made from electrodes on both sides of the joint as opposed to MIG and TIG spots which are made from one side.
Spray transfer A MIG (GMAW) process which has an arc voltage high enough to continuously transfer the electrode metal across the arc in small globules.
Squeeze time In resistance welding, the time, measured in cycles, that the electrodes are under a force to clamp the parts and ensure good electrical flow.
Staggered intermittent welds Intermittent welds made on both sides of a joint that are offset from each other.
Stainless steel A steel alloy containing chromium that resists corrosion and oxidation.
Step down transformer An electrical device used welding machines that reduces voltage and increases amperage in its secondary circuit.
Stick Welding (SMAW or Shielded Metal Arc) A process which melts and joins metal by heating them with an arc between a covered electrode and the workpiece. Shielding gas comes from the electrodeâs outer coating, also known as flux.
Straight polarity An electrode negative cathode, connecting DC current to cause the electrons to flow from the electrode to the base metal.
Strain The reaction of an object to stress.
Strength The ability of a material to withstand applied loads without failure.
Stress The load or force imposed on an object.
Stress relieving Even heating of a structure to a temperature below the critical temperature followed by a slow, even cooling to reduce stresses in the material.
Strike an arc The act of touching the electrode to the workpiece, then withdrawing it a distance sufficient to maintain the electrical flow across the arc.
Stringer bead A bead made by moving the torch or electrode holder along a weld without any side-to-side motion.
Stud arc welding (SW)An arc welding process in which studs, nails, or other fasteners are used as the electrode while they are welded to the surface.Once the base metal melts, the special stud arc gun presses the fastener into the surface.
Submerged Arc Welding (SAW) A process which joins metals by an arc between bare metal electrode and the work. Shielding comes from a granular fusible material.
Surfacing The deposition of a filler metal on a metal surface to obtain desired properties or dimensions.