1. OPITZ PART CODING A systematic method for classifying and retrieving similar components Dr.DurjyodhanSethi Assistant professor Department of Mechatronics Engineering, Sharad Institute of Technology College of Engineering, Ichalkaranji, Opitz Part Coding System | Group Technology

2. Learning Objectives Understand the purpose and structure of the Opitz Part Coding System. Explain the meaning of the five Form-Code digits. Interpret common codes for rotational components. Apply the coding logic to a stepped shaft. Understand how coding supports Group Technology, CAPP and component retrieval. Opitz Part Coding System | Group Technology

3. What is Opitz Part Coding? Opitz is a widely used Group Technology (GT) classification and coding system. It assigns a numerical code to a component based on its geometric and manufacturing characteristics. The first five digits are the Form Code for the component. The code provides a compact representation of the component's shape and important features. Similar codes indicate components with similar design and manufacturing requirements. Opitz Part Coding System | Group Technology

4. Structure of the Opitz Form Code Opitz Part Coding System | Group Technology

5. Digit 1 – Part Class For shaft-type parts, the L/D ratio is important in selecting the first digit. Opitz Part Coding System | Group Technology

6. Digit 2 – External Shape Opitz Part Coding System | Group Technology

7. Digit 3 – Internal Shape Opitz Part Coding System | Group Technology

8. Digit 4 – Plane-Surface Machining Opitz Part Coding System | Group Technology

9. Digit 5 – Auxiliary Holes / Gear Teeth Opitz Part Coding System | Group Technology

10. How to Assign an Opitz Code Step 1: Identify whether the component is rotational or non-rotational. Step 2: For a rotational part, determine the L/D ratio for Digit 1. Step 3: Identify the dominant external shape for Digit 2. Step 4: Identify the internal feature for Digit 3. Step 5: Identify plane-surface machining for Digit 4. Step 6: Identify auxiliary holes or gear teeth for Digit 5. Step 7: Combine the five digits in sequence. Opitz Part Coding System | Group Technology

11. Worked Example – Stepped Shaft Given: cylindrical stepped shaft with one through hole and external thread. Assume 0.5 < L/D < 3. Digit 1 = 1 → rotational part in the specified L/D range. Digit 2 = 5 → stepped external form with thread. Digit 3 = 1 → through hole. Digit 4 = 0 → no plane-surface machining specified. Digit 5 = 0 → no auxiliary holes or gear teeth specified. Opitz Part Coding System | Group Technology

12. Worked Example – Final Code 1 5 1 0 0 OPITZ FORM CODE = 15100 Use the exact coding chart prescribed by your university/textbook. Opitz Part Coding System | Group Technology

13. Why Opitz Coding is Useful Part classification: groups components with similar geometry. Part retrieval: helps designers find existing or similar components. Design standardization: reduces unnecessary duplicate designs. Manufacturing planning: supports identification of similar process requirements. CAPP support: similar parts can share or adapt process plans. GT and cellular manufacturing: helps form part families and machine cells. Opitz Part Coding System | Group Technology

14. Opitz Coding and Group Technology Engineering drawing → Opitz code → Part family Parts with similar codes can be grouped into families. Part families can be associated with similar machines, tools and process plans. This reduces planning effort and can reduce material handling and inter-cell movement. Opitz Part Coding System | Group Technology

15. Short Practice Questions 1. What is the purpose of the Opitz Part Coding System? 2. Explain the significance of Digits 1, 2 and 3. 3. What information is represented by Digits 4 and 5? 4. Apply Opitz coding to a simple rotational component using a supplied coding chart. 5. Explain how Opitz coding supports part-family formation and CAPP. Opitz Part Coding System | Group Technology