Thread Measuring Wires per ASME B89.1.17

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 - 0.86602540P)

Applicable ANSI / ASME Standards:

 B89.1.17  “Measurement of Thread Measuring Wires”

 B1.7M  “Nomenclature, Definitions, & Letter Symbols for Screw Threads”

 B1.1  “Unified Inch Screw Threads (UN & UNR Thread Form) ”

 B1.2  “Gages & Gaging for Unified Inch Screw Threads”

 B1.13M  “Metric Screw Threads: M Profile”

 B1.16M  “Gages & Gaging for Metric M Screw Threads”