The effect of weld nut projection welding means is a combination of a surface of the weldment is processed in advance of one or more projections point to the welding surface of another want to touch \ pressurizing and heating, projection point pressure feed After making these points of contact resistance welding solder method. Key Features: Welding concentricity (visual), weld strength (see test method), thread lossless product name and model specifications Quartet welding nut M4 (small square) 7 * 2 square weld nuts-M4 galvanized (Welding M4) Quartet M8X1.25 square weld nuts Weld nuts 5/16-18