Unit 2 Threaded Fasteners Instructor James Thornburgh Bring
Unit 2 Threaded Fasteners Instructor: James Thornburgh Bring up your Homework & Put on Table
Objectives n n n Define keywords related to Threaded Fasteners List the three classes of fit Describe the differences between course, fine, and extra fine threads Describe the difference between single and multiple thread fasteners List the common information contained in a thread note
Objectives n n n List and identify three different methods to graphically represent threads Identify and draw different types of screws Describe the difference between rivets and screws Draw pipe threads, hex and square bolts and nuts Use thread tables to specify or draw threaded fasteners
What are Threaded Fasteners n Screws n Terminology
Thread Forms
Class of fit n 1 n n n 2 n n n Loose fit For quick assembly High Quality General purpose 3 n n Very High Quality High Precision, stress, or vibration
Thread Pitch n Determines how far a Fastener goes with each revolution
Thread Notes
Metric Thread Note n Pitch is Distance in mm
Thread Grades
Thread Table n http: //www. littlemachineshop. com/Reference/tapdrill. php
Drawing Threads n Detailed Show detailed thread form n Time Consuming n Rarely used n n Schematic n n Easier than Detailed Simplified Easiest to draw n Used most often n
Pipe Threads n Why are they at an angle?
Fastener Types n Bolt n n n Stud n n n Hex or Square Head Used with a nut to Squeeze parts Threaded into a Part Attached second part with a nut Cap Screw n n n Longer than a bolt Threaded to the head Threads into part
Fastener Types n Cap Screw n n Machine Screw n n n Can have Socket Head Smaller than Cap Screw Many different head Styles Set Screw n n With or without a head Used to keep parts still
Square Bolt . 5” dia Sq Hd Bolt
Hex Bolt 1” dia Hex Hd Bolt
Making Nuts and Bolts
Machine Screw Heads
Screw Drive Type
Other Screws n Shoulder n Self Tapping n Wood
References n n http: //www. mcmaster. com http: //www. boltscience. com/ http: //www. Barnhillbolt. com http: //www. fastenal. com
Lab Assignments & Homework n Lab Handout n Workbook 17. 1, 17. 2 inst. On Pg 10 n Prob 17. 2, 17. 8 n n Homework Chapter Questions 1 -17 n Online Multiple Choice Quiz n
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