Posted by Robert Hernandez on Feb 14th 2025
| Term | Definition |
|---|---|
| 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 original hand-held tungsten electrode grinder that delivers crisp arc starts and gives TIG welders better control of the weld puddle. A Sharpie tungsten grinder is one of the easiest ways to 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 reduce 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 units such as millimeters, kilograms, liters, newtons, and pascals. |
| Side bend | A test performed by bending a weld sample 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 material that covers finished shielded metal arc, flux-cored, and submerged arc weld beads. |
| 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 to reduce spatter. |
| Solidus | The temperature at which a metal or alloy begins to melt. The liquidus is the temperature at which the metal becomes completely liquid. |
| Spatter | The scattering of molten metal droplets over the surface near an arc weld. |
| Spot welding | A process typically used on overlapping joint designs where welds are made from electrodes on both sides of the joint. |
| Spray transfer | A MIG (GMAW) process with arc voltage high enough to continuously transfer electrode metal across the arc in small droplets. |
| Squeeze time | In resistance welding, the time that the electrodes are under force to clamp the parts and ensure good electrical flow. |
| Stainless steel | A steel alloy containing chromium that resists corrosion and oxidation. |
|
Stick Welding (SMAW) |
A process which melts and joins metal by heating with an arc between a covered electrode and the workpiece. |
| Strength | The ability of a material to withstand applied loads without failure. |
| Stress | The load or force imposed on an object. |
| Strike an arc | Touching the electrode to the workpiece and withdrawing it to establish electrical flow across the arc. |
| Stringer bead | A bead made by moving the torch or electrode holder along a weld without side-to-side motion. |
| Stud arc welding | An arc welding process in which studs or fasteners are welded to a surface and pressed into the molten base metal. |
|
Submerged Arc Welding (SAW) |
A process which joins metals by an arc between a bare metal electrode and the work, shielded by granular flux. |
| Surfacing | The deposition of filler metal on a metal surface to obtain desired properties or dimensions. |
