Thread Terminology
The top surface of the Thread
What is the Crest
_____ is the standard profile of the thread
What is Thread form?
specifies the amount of tolerance permitted in engagement between mating threads
What is Thread Class?
3/4-10UNC-2BT1
The 3/4 In this equation specifics:
The Major Diameter of the treads
The bottom surface of the Thread between two sides, or flanks, of the tread.
What is the root?
Classification of threads in a thread system
What is a thread series?
The class designations for external threads
What are 1A, 2A, 3A?
3/4-10UNC-2BT1
The 10 In this equation specifics:
The distance from one point of the tread to the corresponding point on the next tread.
What is the pitch.
The company that designates the standard for thread forms.
American National Standard Institute (ANSI)
The class designations for internal threads.
What are 1B, 2B, 3B?
3/4-10UNC-2BT1
The UNC In this equation specifics:
The tread form and series
The smallest diameter of the tread, measured root to root for external thread or from crest to crest for internal tread.
What is the Minor Diameter.
The unit used to specify Pitch.
What is threads per inch (TPI)?
The classes that have the most amount of tolerance.
What are 1A and 1B?
3/4-10UNC-2BT1
The 2B In this equation specifics:
The Tread class.
The axial distance the tread advances in one complete revolution.
What is the Lead?
The four main series in the unified system.
What are Unified course (UNC), Unified fine (UNF), Unifed ultra fine (UNEF), and Unified constant pitch (UN)?
The classes the require the tightest tolerance.
What are 3A and 3B?
3/4-10UNC-2BT1
The T1 In this equation specifics: