Machinery part drawing is the basis for manufacturing and testing mechanical parts, and the carrier reflecting the structure, size and technical requirements of mechanical parts. The purpose of reading the parts drawing is to imagine the structure shape of the parts according to the parts drawing, understand the size and technical requirements of the parts, so as to guide production and solve technical problems, which is the quality of mechanical engineering technicians and manufacturing enterprises should have.

Method and procedure of understanding part drawing: 

(1) Summary understanding - from the title bar to understand the name of the part, material, proportion, etc. Roughly understand the use of parts from the name; From the material, the general method of manufacture is known; The size of the part can be estimated from the drawing scale.

(2) Analyze the view and imagine the structure shape of the parts -- first find the main view, then analyze each view of the parts, make clear their view name, cutting position, projection relationship and the content expressed. The relative position of the structure is analyzed by the form analysis method and the line and surface analysis method, and then the overall structure shape of the parts is figured out.

(3) Size analysis -- analysis of the overall size of the parts, shape size, positioning size, size reference and the main size of the parts, clear the size of each part.

(4) Analysis of technical requirements -- analysis of parts of the size limit requirements and geometric tolerance, surface structure and other technical requirements and quality indicators.

(5) summarize -- to sum up, all aspects of the obtained data are summarized and analyzed, so that we can have a complete understanding of the overall appearance of the parts, and form the overall shape of the parts in our mind.