The design and engineering parameters of free forging are considered as follows: 1. Material selection: Select the appropriate material according to the use requirements of the parts and the working environment. Consider the strength, toughness, wear resistance, corrosion resistance and other characteristics of the material. 2. Shape design: According to the functions and dimensions of the parts, design a reasonable geometric shape. Taking into account the stress of the parts, to avoid stress concentration, deformation and other problems. 3. Process selection: Select the appropriate forging process to manufacture free forgings. Consider forging temperature, pressure, speed and other parameters as well as subsequent heat treatment process. 4. Design parameters: According to the use requirements of the parts and the force situation, determine the reasonable size, weight, wall thickness, rounded radius and other design parameters. 5. Machining allowance: Considering the processing process after forging, it is necessary to increase the appropriate machining allowance to ensure the accuracy of the final size and shape. 6. Heat treatment process: According to the characteristics of the material and the requirements of the use of parts, choose the appropriate heat treatment process to improve the mechanical properties and wear resistance of the material. 7. Surface treatment: According to the use environment and requirements of the parts, choose the appropriate surface treatment process, such as coating, spraying, etc., to improve the corrosion resistance and beauty of the parts. 8. Quality control: Through material testing, forging process control, heat treatment control and final product inspection, etc., to ensure that the quality of free forging meets the design and use requirements. The above factors are the main factors to be considered in the design and engineering parameters of free forging, and the performance and reliability of free forging can be guaranteed through reasonable design and engineering parameter selection.