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Basic 60°Thread Measuring Wire Information
PITCH DIAMETER = MEASUREMENT OVER WIRES (MOW) - CONSTANT
w = Wire Size
P =Pitch = 1 / # of Threads per Inch = The distance the Thread travels in one turn.
C = Constant = 3w - .86602540P
PD = Pitch Diameter = the halfway point between Sharp Major & Minor Diameters.
Measured PD = MOW - (3w - .86602540P)
Reference ANSI / ASME Standards:
B89.1.17 - 2001 "Measurement of Thread Measuring Wires"
B1.7M - 1984 "Nomenclature, Definitions, & Letter Symbols for Screw Threads"
B1.1 - 2003 "Unified Inch Screw Threads (UN & UNR Thread Form) "
B1.2 - 1983 "Gages & Gaging for Unified Inch Screw Threads"
B1.13M - 2001 "Metric Screw Threads: M Profile"
B1.16M - 1984 "Gages & Gaging for Metric M Screw Threads"