In machining, "feeds and speeds" refers to the parameters used to control the rate of material removal during the cutting process. It involves determining the appropriate values for feed rate and cutting speed to achieve efficient and accurate machining operations.
Feed Rate: The feed rate, often expressed in units of distance per unit of time (e.g., inches per minute or millimeters per revolution), represents the linear speed at which the cutting tool moves along the workpiece. It determines how quickly the tool advances into the material, affecting the depth of cut and the time required to complete the operation.
Cutting Speed: The cutting speed is the relative speed at which the cutting tool and the workpiece move relative to each other along the cutting edge. It is usually measured in surface feet per minute (SFPM) or meters per minute (m/min). Cutting speed directly influences the tool's engagement with the material and affects factors such as tool life, heat generation, and surface finish.
The feeds and speeds parameters are determined based on various factors, including the type of material being machined, the tooling used, the desired surface finish, the rigidity of the machine, and the specific machining operation being performed (e.g., milling, turning, drilling).
Optimizing feeds and speeds is crucial to achieve efficient machining. Using excessively high feed rates or cutting speeds can result in tool wear, poor surface finish, and even tool breakage. On the other hand, using too low values may lead to slow production rates and inadequate material removal.
Machinists typically rely on machining handbooks, cutting tool manufacturers' recommendations, or specialized software to determine appropriate feeds and speeds for specific machining applications. These references provide guidelines based on years of experience and testing to help achieve optimal cutting conditions for different materials and tools.