Portland Community College | Portland, Oregon

Cutting External Threads - Cutting (or chasing) a thread refers to the operation of machining thread with a single point cutting tool on the lathe. This is an operation that is done frequently in lathe work. In this module, the student will learn about threads and thread forms and how to chase an external thread.

Cutting Internal Threads - The cutting (or chasing) of screw threads is an important part of the machinist's work. The cutting of internal screw threads is done in nuts and castings. In this module, the student will learn how to cut internal screw threads.

Thread Forming - The Forming (or Rolling) of screw threads is an important part of the machinist's work. The forming of internal and external screw threads is done in nuts, bolts, fasteners and castings. In this module, the student will learn how to form internal and external screw threads.  

PREREQUISITE SKILLS AND KNOWLEDGE:  
MCH180  

The student will be able to turn safely and accurately an exercise piece to print specifications, using the set-up methods and proper tools used for producing internal and external threads.  

This course is based on performance outcomes. The following performance outcomes are based upon established industry standards. The student will demonstrate knowledge and understanding through the following activities:

• Given the necessary materials, tools, and equipment, the student will use the lathe to cut external threads to print specifications.
• Given the necessary materials, tools, and equipment, the student will use the lathe to cut internal threads to print specifications.
• Given the necessary materials, tools, and equipment, the student will use the lathe to form internal and external threads to print specifications.  

Threading on the lathe will be presented by means of audio-visual presentations, demonstrations, lab experiences, and research activities. The course activities and design emphasize the development of skills and knowledge outcomes prescribed by established industry standards. The identified outcomes will be achieved by means of individual and team activities.

POLICY - Student performance measurements are based on established industry standards. The various areas of study during the course will be evaluated by a variety of activities. Typical of those activities are the following;

1. READING ASSIGNMENTS - Information sheets, textbooks, journal articles and the learning resource center are potential sources of information that the student will reference as directed in the modules identified in the introduction. 

2. PRACTICE - Completion of tasks and projects identified in the reading assignments, information sheets, journal articles and textbooks. Students are require dot complete practice activities with 100% competency.

3. SELF-ASSESSMENT - Checking and evaluating the students understanding and knowledge gained through the reading assignments and practices typically done through a practice evaluation.

4. LAB ACTIVITIES - Participation in structured laboratory exercises with the emphasis on developing skills or increasing expertise in the areas of study identified in the module packets.

5. FINAL ASSESSMENT - An assessment in the form of a written exam and/or practical application that addresses the subject areas identified in the module packets. Students are required to complete final assessment activities with 85% competency.  

TEXT:

Machinery's Handbook

Technology of Machine Tools by Krar, Oswald, and St.Amand

Machine Tool Practices, by Kibbe, Neely, Meyer, and White