Thread Milling Tool selection
[Form]
[Size]
[Thread length]
[Non standard]
[Find Tool]
[Order by]
[Custom tool]
[Max tool dia]
[Left Right]
[Inner Outer]
[Inch Metric]
[NC program]
[Technical details]
The programlet assist you to select or define your threadmilling tool, and also to develop
the NC code for the actual threadmilling.
The program comes up with the tool selection table:
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First select the form
(default is UN for web version, or the selection form the last session for the sandtalone version).
The following forms are supported:
Tool Forms
Select a form by clicking on the name |
| Form |
Description |
Angle |
Dim |
Size format |
| UN | American Standard Unified Threads | 60 | inch | given |
| UN_special | American Standard Unified Threads | 60 | inch | <dia> - <tpi> |
| NPT | American National Standard Taper Pipe Threads | 60 | inch | given |
| NPTF | American National Standard Taper Dryseal Pipe Threads | 60 | inch | given |
| NPS | American National Standard Pipe Threads | 60 | inch | given |
| NPSF | American National Standard Dryseal Pipe Threads | 60 | inch | given |
| ISO | ISO Standard Metric Threads | 60 | mm | <dia> x <pitch> |
| ISO_special | ISO Standard Metric Threads | 60 | mm | given |
| BSP | British Standard Pipe Screw Threads | 55 | inch | given |
| BSPT | British Standard Tapered Pipe Screw Threads | 55 | inch | given |
| ACMEFULL | American National Standard General Purpose ACME Full Threads | 29 | inch | <dia> - <tpi> |
| ACMESTUB | American National Standard General Purpose ACME Stub Threads | 29 | inch | <dia> - <tpi> |
| BUTTRESS | American Buttres 45-7 Threads | 45-7 | inch | <dia> - <tpi> |
Selecting the form will automatically select the default
Size, Thread length, Major and Minor diameters.
The tool data (Tool dia, Cutting length, Flutes) are set to zero.
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Second select size.
Click one of the choices,
or enter the standard size
- <dia inch> - <thred per inch>
format for UN
- <dia mm>> x <pitch mm>
format for ISO
Selecting the size will automatically select the calculated standard
Major and Minor diameters and also
for NPT, NPTF, NPS, NPSF, BSP and BSPT forms the
Thread length parameter. For the rest of the
forms the default length comes up, it shall be changed to the
appropriate value. Please note, that for tapered inner threads the
major and minor diameters are measured at the bottom of the engagement,
so 2 or 3 threads above the bottom Z level;
for tapered outer threads the major and minor diameters are at the top Z level,
when the thread is machined.
When new form or size is selected, the tool data
(Tool dia, Cutting length, Flutes) are set to zero.
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Changing Size always changes
Major and Minor diameters and with the exception of
UN, UN_special, ISO, ISO_spacial, ACMEFULL, ACMESTUB, BUTTRESS forms, changes
thread length
parameter too.
If your thread has non standard
Major and Minor diameters, check the
Non standard checkbox, and modify the diameters.
Thread lenght may be changed w/o checking
Non standard box.
Please note, that
- for Inner thread the predrilled hole
has to be at least Minor diameter large, and the thread will be
cut to Major diameter size
- for Outer thread the pre-mashined cylinder
has to be at most Major diameter large, and the thread will be
cut to Minor diameter size.
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Third enter or check Thread length.
For NPT, NPTF, NPS, NPSF, BSP, BSPT, ACMEFULL, ACMESTUB
forms the standard size is set by
selection, for others the correct size has to be entered.
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If the thread is defined properly by selecting Form and Size
parameters, entering Thread length and if necessary
making the modifications for Major and Minor diameters
then click Find Tool tab.
If there is at least one tool in the database, capable of machining the defined thread,
the programlet comes up with the list of the available tools.
The tool must have
- the same size (tpi for inch or pitch for metric) at the thread
- at least the same cutting length as the thread length
- for inner therads the diameter must be no larger than the given percentile of the
minor diameter, and less than
minor diameter - 2 * safety distance.
The first tool in the list is automatically selected, and tool data
(Tool dia, Cutting length, Flutes)
are set accordingly. Click on a photo
to select a different tool.
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If you click ORDER BY
link, you may select different orders for the tools shown
Clicking on a radio box, immediatelly brings up the new selection order.
As default only 3 tools are shown, clicking on List all
link will bring up all the available tools.
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Tool selection always set Tool diameter, Cutting length and Flutes
parameters.
If there is no available tool in the database, or you want to use your custom tool,
enter tool data and select one of the Custom tool options
Selected tool option requires Find tool command and tool selection
any of options determines the tool with the given stayle
and to enter the tool parameters:
- For inner thread Tool diameter
must be less than Minor diameter (predrilled hole),
for outer threads there is no such requirement.
- Cutting length has to be positive nonzero decimal,
if this equals or exceeds Thread Length
the thread will be cut by one full circle, otherwise the threadcutting will need multiple full circles.
If you set Cutting length to a positive nonzero
value less than the pitch amount, the program will generate as many
helical arcs as is necessary to
cut the full thread length by the one thread tool.
- Flutes input for NC program must be positive nonzero integer,
optionally followed by / En parameter, where n is the number of skipped tools + 1.
This format is set by tool selection, or had to select as custom tool option.
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Minor dia / Tooldia % parameter determines the maximum size
of the tool for a given inner thread, in terms as percentile
of the Minor diameter. The number should be positive decimal less than
1.0. If the tool is larger than Minor diameter - safety distance,
this later defaults to .01 inch or .254 mm.
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Handedness.
- Lefthanded tools are
cut by CCW (G03) movements in conventional milling
and CW (G02) movements in climb milling. Usually
only tools of moving parts are lefthanded.
- Righthanded tools are
cut by CW (G02) movements in conventional milling
and CCW (G03)movements in climb milling.
Most tools are right handed.
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Inner outer radiobuttons select the thread type
repsented by the accompanied images
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Inch - metric radiobuttons change the dimension
for Thread length, Major diameter, Minor diameter, Engagement, Tool-dia, Cutting length
variables. Pitch variable in the
tool selection table is unchanged
(1/tpi or metric value for ISO threads), however, for the
NC program table inch/metric change will change the pitch too.
T.A.D.M.N.
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