Question

Problem 1) (a) Fill in the given table for the following external threads. e following external threads. Thread class=3 (6 points) Major Series #12 Coarse Thread Note Tap drill size and/or diameter Pitch (b) Fill in the given table for the following external threads. (6 points) Major Ø Series M14 Fine Thread Note Tap drill size and/or diameter Minor Diameter

Answer 1

Major a series #12 course Thread Note - 24UNC 3 A Tap drill size 4.65mm or 0.184 inch. pitch 1.058mm or 0.0417 inch). 24 threads per luch. UNCS unified course 3 class of thread. A > External thread Tap drill size= M14 Thread Note | M14X 1.25 Drill size 12.8mm. pitch 1.25

• Major diameter #12 ( from standard table ) (7/32 - 24 UNC 3 A )
• coarse series :
• 7/32 = Major diameter in inch.()
• 24 = Threads per inch (TPI)
• UNC= Unified Coarse thread type
• 3 Class of thread
• A for External thread (B for internal thread)
• Drill size can be calculated by(Substrat  the pitch from major diameter ) = major diameter - pitch

• For M14 fine series (M14 1.25  )
• M = Metric thread (form of thread)
• 14 = Major diameter
• 1. 25= pitch
• drill size = 12.8
• NOTE ( for coarse thread note the pitch will be replaced by the length of thread    ) for example for metric coarse thread note representation M14 XX ( XX = thread length)