NOTE: MULTIPLYING the constant by the
The following formulas will provide the informa-
pitch, as in the preceding formulas, produces the same
tion you need for cutting V-form threads:
result as if you divide the constant by the number of
1. V-sharp thread
threads per inch.
To produce the correct thread profile, you must
1
Pitch = n or 1 number of threads per
use a tool accurately ground to the correct angle and
contour. Also, you must set the cutting tool in the
inch
Straight Depth of thread = 0.866 pitch
be ground and set. Remember, if you are using a
2. American National Thread
Pitch = 1 number of threads per inch
Straight depth of external thread
= 0.64952 pitch or 064952p
Straight depth of internal thread
= 0.541266 pitch or 0.541266p
Width of flat at point of tool for external and
internal threads = 0.125 pitch or 0.125p
Slant depth of external thread = 0.750
pitch or 0.750p
Slant depth of internal thread = 0.625
pitch or 0.625p
3. American Standard Unified
Pitch = 1 number of threads per inch
1
or n
Straight depth of external thread = 0.61343
inch pitch or 0.61343p
Straight depth of internal thread = 0.54127
inch pitch or 0.54127p
Width of flat at root of external thread
= 0.125 inch pitch or 0.125p
Width of flat at crest of external thread
= 0.125 inch pitch or 0.125p
Double height of external thread = 1.22687
inch pitch or 1.22687p
Double height of internal thread = 1.08253
inch pitch or 1.08253p
Slant depth of external thread = 0.708
pitch or 0.708p
Slant depth of internal thread = 0.625
Figure 6-82.--Threading tool setup for V-form threads.
pitch or 0.625p
6-49