Glossary 879 Resistance soldering: A soldering process that relies on electrical resistance in the base metal to provide heating to melt the solder. When the solder begins to fl ow, the electric current is stopped. Resistance spot welding (RSW): A resistance welding process that uses resistance to the fl ow of electricity to create the heat for fusion. A small spot is welded on two overlapping pieces between two electrodes. Resistance welding: Process that uses the resistance of the metals to the fl ow of electricity as the source of heat. Resistance welding schedule: In resistance welding, the sequence of events that must occur to complete one weld. Right side view: The view on a working drawing that shows the shape and size of an object’s right side. Rigid tubing: Tubing that cannot be bent effectively. Robot: A mechanical device that can perform various movements at the direction of an automatic controller. Robotics: The use of robots and automatic controllers, along with tools like welding torches or guns, to perform welds, cuts, or machining operations. Robot work cell: The volume of space in which the robot, positioner, controller, and all other related components are located. Rockwell B test: Rockwell hardness test that uses a 1/16″ (1.6mm) diameter ball indenter and a major load of 100kg (220 lbs). It is used on materials like copper alloys, soft steels, and aluminum alloys. Rockwell C test: Rockwell hardness test that uses a diamond ground to a 120° point and a major load of 150kg (331 lbs). It is used on materials like steel, deep case-hardened steel, hard cast irons, and titanium. Rockwell hardness tester: Tester that measures the hard- ness of materials, based on depth of penetration of a standardized force. Rolling mill: A machine that rolls ingots between large powerful rollers, reducing them to the required shape. Root: Bottom of the weld. Root crack: Crack in either the weld or the heat-affected zone at the root of a weld. Root face: The distance from the weld root to the point where the bevel angle begins. Root of joint: Point at which metals to be joined by a weld are closest together. Root of weld: That part of a weld farthest from the source of weld heat and/or from the side where fi ller metal is added. Root opening: The space at the bottom of the joint between the pieces being welded. Root pass: The fi rst weld pass in a multipass weld. Root penetration: Depth to which weld metal extends into the root of a welded joint. Root reinforcement: The distance that the penetration proj- ects from the root side of the joint. Rosette weld: See Plug weld. Rosin: A translucent, gelatin-like chemical compound that can be used to clean the surface of a base metal by removing various contaminants prior to soldering. Rosin-based fl uxes: Fluxes that are the least effective in cleaning off metal oxides or tarnishes. Rotor: The rotating part of an electrical generator. Run-off tab: A piece of metal, the same type and thickness as the base metal, that is tack welded to the end of the weldment where the weld bead will end. Run-on tab: A piece of metal, the same type and thickness as the base metal, that is tacked onto the end of the weld- ment where the weld bead will begin. S Safety inspection: An inspection of a welding station or welding area to detect damage to equipment or other unsafe conditions. Saturable reactor control: Transformer output control method in which a low-voltage, low-amperage dc current is used in the control circuit. When the dc current is changed, the magnetic fi eld in the reactor is changed, which in turn changes the secondary output current. Scale: Oxide coating. Also, a tool used for measuring length, mass, or weight of an object. Scleroscope test: Hardness test that uses the height of rebound of a falling piece of metal to determine how much energy is absorbed by the material being tested. SCR: See Silicon-controlled rectifi er. Scratching motion: Technique used to initiate an arc between an electrode and base metal. Seam weld: A weld made by resistance seam welding or made from one side by melting through the fi rst piece and melting into the second piece. Seam welding: Welding method that produces a contin- uous or intermittent seam. Seam welding machine: A resistance welding machine that uses two copper alloy wheels as electrodes. The wheels press two pieces of metal together and roll slowly along the seam. Current is passed, either continuously or at timed intervals, between the electrodes and work. Secondary hardening: The process of tempering of some alloy steels at a higher temperature than normally used for hardening. The result is a hardness greater than is achieved by tempering at the lower temperature for the same period of time. Section lines: Thin lines, 0.012″ (0.3mm) thick, that show solid, cutaway surfaces in a section view. Self-shielded fl ux cored arc welding (FCAW-S): FCAW process in which the weld is shielded with gases formed when the fl uxing agents within the hollow electrode vaporize in the heat of the arc. Semiautomatic cutting: As electronic and magnetic tracers follow a pattern, electric motors move the torch or torches to cut the metal in the same shape as the pattern. Some changes to the process may be required while cutting is taking place. Semiautomatic welding: Manual welding with one or more of the welding variables controlled by automatic devices. Semikilled steel: Incompletely deoxidized steel that contains suffi cient dissolved oxygen to react with the carbon, so that carbon monoxide is formed. This offsets solidifi cation shrinkage.