What are the Meanings of References in Custom CNC Machining Mechanical Parts?

What are the Meanings of References in Machining Mechanical Parts? What is a Reference?

A reference is a widely used concept in the machinery manufacturing industry. The concept of a reference applies to mechanical products, from dimension marking in design, workpiece positioning in manufacturing, dimensional measurement in calibration, to determining the assembly positions of parts. A reference is a point, line, or surface used to establish geometric relationships on a production object. Based on different reference surfaces, standards can be divided into design standards and process standards. Here are the details:

1. Design Reference: The design reference is used to determine the positions of other points, lines, and surfaces on the part drawing. For shaft sleeve components processed in Shanghai, the design basis for each outer ring and inner hole is the axis of the part. End face A serves as the design basis for end faces B and C, while the axis of the inner hole is the basis for measuring the radial runout of the outer ring.
2. Process Reference: This refers to the references used during the machining and assembly processes, known as process references. Depending on their use, process references can be divided into assembly references, measurement references, and positioning references.
3. Assembly Reference: This is the reference used during assembly to determine the position of components or parts within a product, known as the assembly reference.
4. Measurement Reference: This is the reference used to check the dimensions and positions of machined surfaces, known as the measurement reference. The axis of the inner hole serves as the measurement reference for checking the radial runout of the outer ring, while surface A is the measurement reference for checking length L and dimension L.