root edge.A root face of zero width. See root face. root face.That portion of the groove face adjacent to the root of the joint. root of joint.That portion of a joint to be welded where the members approach closest to each other. In cross section the root of the joint may be either a point, a line or an area. root of weld.The points, as shown in cross section, at which the back of the weld intersects the base metal surfaces. root opening.The separation between the members to be joined at the root of the joint.
11 of 15 root penetration.The depth that a weld extends into the root of a joint measured on the centerline of the root cross section. root reinforcement.Reinforcement of weld at the side other than that from which welding was done. root surface.The exposed surface of a weld on the side other than that from which welding was done. Sscarf joint.A form of 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. semi-blind joint.A joint in which one extremity of the joint is not visible. series 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. 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.