Spot and projection welders are both referred to as resistance welders , which differ from each other in welding processes and the different forms of non-equipment.
Spot welding is a common method of lap (overlap) welding (joining) of plates, which can be single point or multi-point welding and be used in AC welding machine medium frequency welding machine.
Projection welding is a projection point on one side and a flat plate on the other side. The projection point is a concentration of current, thus improving thermal efficiency and facilitating welding. Our common car nut projection welding is a typical projection welding process on a flat plate. Usually m edium frequency welding and energy storage welding machine are available.
Spot welding and projection welding can meet the welding requirements of both processes with the same welder. On the market, we distinguish between spot or projection welding machines due to the complete level of equipment quality. Projection welding is a hard standard welding requirement featuring high pressure, high current and short welding time. While spot welding is a soft standard welding requirement which uses equipment with low current to extend time to form a molten core and meet the welding requirements.
Therefore, compared to the spot welder, the projection welder requires higher steel, current control accuracy and current creep speed, which increases the cost of the equipment.