50 —
M
achinist
c
alc™
P
ro
3-Wire Measurement –
Known Thread Size and Wire Size
You can find the Minimum and Maximum 3-Wire Measurements
as well as the Pitch Diameters if you know the Thread Size and
the Wire Size you want to use.
Note:
When solving for 3-Wire Measurements and Pitch Diameters, the
calculator assumes the equivalent External Thread Type if an Internal
Thread Type is set (i.e., Internal 2B is assumed External 2A for U.S.
Threads; Internal 6H is assumed External 6H for Metric Threads).
Find the Minimum and Maximum allowable 3-Wire
Measurements and Pitch Diameters for a 3/8
-
16, Class 2A
(External) screw using 0.040" wire:
KeySTROKe
DISPLAy
O O
0.
1. Enter the Thread Size:
3 / 8 t
SIZe
3/8 –
INCH
2. Enter the Threads per Inch and store the final Thread Size:
1 6 t
THReD
SIZe
$
3/8 –
16
INCH
3. Set the Thread Class to 2A:
2 g b
* (Thread Class)
eXT 2A
* If necessary, continue pressing
b
until the desired External Thread
Class is displayed.
4. Enter the Wire Size*:
. 0 4 g f
(Wire Size)
WIRe
SIZe
$
0.04
INCH
5. Find the Minimum 3-Wire Measurement:
g R
(3-W Measure)
3WMIN
SIZe
0.3946
INCH
6. Find the Maximum 3-Wire Measurement:
R
3WMAX
SIZe
0.3990
INCH
7. Find the Minimum Pitch Diameter:
R
PTCH-
SIZe
0.3287
INCH