Operation Manual

HEIDENHAIN CNC PILOT 4290 687
11.1 Undercut and Thread Parameters
Thread Parameters
To determine the thread parameters, the CNC PILOT uses the
following table;
Where:
 F: Thread pitch. Where an asterisk “*” is given in the table, the
thread pitch is calculated from the diameter, depending on the
thread type (see “Thread pitch” on page 688) .
 P: Thread depth
 R: Thread width
 A: Thread angle, left
 W: Thread angle, right
Calculation formula: Kb = 0.26384*F – 0.1*÷ F
Thread backlash "ac" (depending on thread pitch):
 Thread pitch <= 1: ac = 0.15
 Thread pitch <= 2: ac = 0.25
 Thread pitch <= 6: ac = 0.5
 Thread pitch <= 13: ac = 1
Thread type Q F P R A W
Q=1 Metric ISO fine-pitch thread External – 0.61343*F F 30° 30°
Internal – 0.54127*F F 30° 30°
Q=2 Metric ISO thread External * 0.61343*F F 30° 30°
Internal * 0.54127*F F 30° 30°
Q=3 Metric ISO tapered thread External – 0.61343*F F 30° 30°
Q=4 Metric ISO tapered fine-pitch thread – 0.61343*F F 30° 30°
Q=5 Metric ISO trapezoid thread External – 0.5*F+ac 0.633*F 15° 15°
Internal – 0.5*F+ac 0.633*F 15° 15°
Q=6 Flat metric trapezoid thread External – 0.3*F+ac 0.527*F 15° 15°
Internal – 0.3*F+ac 0.527*F 15° 15°
Q=7 Metric buttress thread External – 0.86777*F 0.73616*F 3° 30°
Internal – 0.75*F F–Kb 30° 3°
Q=8 Cylindrical round thread External * 0.5*F F 15° 15°
Internal * 0.5*F F 15° 15°
Q=9 Cylindrical Whitworth thread External * 0.64033*F F 27.5° 27.5°
Internal * 0.64033*F F 27.5° 27.5°
Q=10 Tapered Whitworth thread External * 0.640327*F F 27.5° 27.5°
Q=11 Whitworth pipe thread External * 0.640327*F F 27.5° 27.5°
Internal * 0.640327*F F 27.5° 27.5°
Q=12 Nonstandard thread – – – – –
Q=13 UNC US coarse thread External * 0.61343*F F 30° 30°