Thread 3-Wire Method & Pitch Diameter Calculator
Calculate Best Wire Size (G), theoretical measurement over wires (M), and actual pitch diameter (E) for 60° Unified Inch (UNC/UNF) and ISO Metric screw threads according to ASME B1.1 and ASME B1.13M standards.
Thread Geometry & Wire Measurement
Inches
Inches
Inches
Measurement over the 3 wires seated in thread grooves.
Actual Measured Pitch Diameter (E)
TARGET NOMINAL: 0.4500"
0.4500 in
Delta from nominal: 0.0000" (Exact target size)
Theoretical Best Wire Size (G)
0.0444 in
0.57735 × Pitch (contacts pitch line)
Theoretical Target Over Wires
0.5184 in
Target micrometer measurement
Thread Inspection Constants
Thread Pitch (P):
0.0769 in
Wire Constant (3W - 0.866025×P):
0.0684 in