Grade/Class:Sophmore Date: Lesson No.:______________

Lesson Plan Outline Topic: Basic Thread Information

Objectives (Student should be able to:) Define and describe the basic parts and functions of the American Standard Screw Thread.

Introduction (Motivation of students) The screw thread is the basic item which all machines function on and the importance of the thread and having a clear understanding of it's parts and functions can not be overemphasized.

Presentation (Teaching points) USE TRANSPARIENCY #6817 FOR THIS PORTION

Pitch of the thread. a. Defined as the distance from any point of a thread to the corresponding point of the next ajacent thread.

b. On single start threads the pitch is the same as the lead. Lead of the thread. a. the distance s thread advances in one turn. Use nut of bolt to demonstrate. ex. the lead of a 1/4-20 of .050, of a 3/4-10 is .100 etc.

Major Dia. a. the largest diameter of any thread.

Minor Dia. a. the smallest diameter of any thread.

Pitch diameter. a. the diameter which when drawn through the threads will produce an equal dimemsion in the thread and trough. It is equal to the major dia minus an amount equal to the single depth of the thread.

Crest. a.. the top surface of the thread.

Root a. the bottom of the thread

Side a. the surface which conects the crest and root.

Depth of the thread a. the distance from the crest to the root.

Application & Feedback (How student will practice content presented)

Add in here several examples of using the various thread formulas. About 5 for each formula. pitch helix angle depth of thread .866 x pitch

Assigments (To do for next class) read ahead about acme, 29 degree worm and square threads. Evaluation (How to measure attainment of lesson objectives) quiz using formulas worked on above.