A grinder machine used for welding is typically referred to as an angle grinder or a grinding wheel. It is a handheld power tool that is commonly used in welding and metalworking applications. Here are some of the purposes and uses of a grinder machine in welding:

Weld preparation: Before welding, the grinder machine is used to prepare the metal surfaces by removing any rust, paint, or coatings. It helps to clean and smooth the welding area, ensuring better adhesion and quality of the weld.

Weld cleanup: After welding, the grinder machine is used to remove any excess weld material or slag. It helps to clean up the weld bead and achieve a smoother, more finished appearance.

Joint shaping: In some cases, the grinder machine can be used to shape or bevel the edges of the metal pieces being welded. This is done to create a groove or angle that allows for better penetration and stronger weld joints.

Weld defect repair: If there are any welding defects such as porosity, undercut, or excessive reinforcement, the grinder machine can be used to remove and repair these imperfections. It helps to improve the quality and integrity of the weld.

Metal cutting: In addition to grinding, some grinder machines can also be equipped with cutting discs or wheels. This allows for cutting through metal pieces or removing unwanted sections during welding or fabrication processes.

It is important to note that using a grinder machine for welding requires proper safety precautions. Operators should wear appropriate protective gear such as safety glasses, gloves, and a face shield. Additionally, it is crucial to follow the manufacturer’s instructions and guidelines for operating the grinder machine safely.