VARIOUS FUNCTIONS AND
PRECAUTIONS OF Symbolic FAPT
2. CAUTIONS FOR USING
D1: First threading depth (Absolute quantity: Material file)
Di: i–th threading depth (Absolute quantity)
Dk: Threading depth once before the last
Dȏ: Last threading depth (Incremental quantity: system parameter)
Since Dk is not calculated by the above equation, it is possible that Dk
becomes an increment smaller than Dȏ.
The thread depth is calculated using the formula: Pitch * constant 0.6495
(system parameter No. 0125 = variable). As a result, the root diameter is
determined. Both external and internal threads are calculated using the
For internal threads, therefore, obtain their thread depth from the thread
pitch and constant 0.6495 to determine the internal thread to be entered
as a figure element.
When asking of screw thread depth, automatically calculated contents
which is displayed on CRT can be changed.
M20, P: Pitch
Minor diameter of internal
thread is calculated by the
Inner dia. = 20 – (P x 0.6495)
Even in the case when the depth of screw thread is input
from keys (not automatically calculated value), recalculation
is executed by inputting multiplier or pitch. In this case, the
required depth of screw thread must be input from keys.
Depth of Screw Thread