Introduction
Stepped mandrels are an effective and efficient way to produce complex shapes and tight tolerances in components. This process allows manufacturers to fabricate the highest quality objects for all sorts of applications, such as medical equipment, industrial machinery, and automotive components. In stepped mandrel fabrication, molten material is injected or ‘poured’ into a particular area (such as a die, mold, or even a tube) and set in place. Heat and pressure are then used to solidify and firm up the component, after which it can be machined to exact specifications. Stepped mandrels are extremely useful in areas where cost, quality, and fast turnover are a priority.
Material Selection
The type of material used in stepped mandrel fabrication must be chosen carefully. Factors such as operating temperature, environmental conditions, and other pertinent criteria must be considered to ensure the finished component will meet exact specifications. Electric-Resistance Welding (ERW) is one common process used in the step mandrel process. In this method, two pieces of metal are pressed together and heated using electric current. The heat melts the material, and pressure from the lower press is then used to combine them and form a single component.
The operator must also consider the type of material being used and determine the best method to reach the desired output. For instance, brass and stainless steel are both commonly used metals as they are highly resistant to corrosion and do not require special heat treatments. Copper is also an option as it has excellent electrical properties. Molded plastic can also work in a limited capacity but often requires more input of material to achieve the desired shape.
Press Selection
The type of press and degree of pressure used in stepped mandrel fabrication will depend largely on the material and component being produced. Heat-treated steel is typically produced in hydraulic presses, with the operator adjusting the degree of pressure. Those used for plastic components may be either hydraulic or electromechanical. Regardless of the material being fabricated, the operator will need to accurately determine the correct pressure in order to properly form the component without any damage.
In the case of an ERW process, the press should be adjusted accordingly to allow for sufficient heat to fill and seal the material. This can be done using a combination of mechanical pressure and heat, with the goal of ensuring an even weld and a good seal.
Machining
In order to ensure the component meets specifications and has a uniform shape and finish, a continual process of machining is required. During this step, the operator will use CNC (computer numerical control) machines to cut, shape, and trim excess material from the component. This machining process can also involve polishing and buffing the component until it meets the desired surface finish. Once this is done, the component should be thoroughly inspected to ensure it is free of defects.
Conclusion
Stepped mandrel fabrication is a highly specialized process used to produce complex shapes and tight tolerances in metal and plastic components. This requires selecting the proper material, press, and machining processes to ensure the finished product meets exact specifications. If done correctly, it can be an extremely useful and cost-effective method of producing high-quality components.
