Manually Adding the Tool List
Some older CAD programs separate the tool information into two files. One file contains hole locations, and the other contains the tool size information. We expect the Excellon/NC drill file to be completely self-contained, so we don’t automatically look for a tool list file.
Our site will detect and reject drill files that don’t contain tool size information, so in the case of split files, you shouldn’t be able to accidentally place an order.
Drill Tool Information
Since these files are often “human readable” files, they vary significantly in how they’re presented. Typically, they’re presented in a table format similar to this one.
# Tool code Size (inches) No. of holes T1 0.0300 13 T2 0.0350 200 T3 0.1181 6
Drill Location File
% T1 X009421Y004444 X007221Y006645 X008715Y005151 T2 X009280Y000526 T3 X011065Y000526 X003475Y002192
Combining the Drill Files
To correct the drill file, use a text editor to open both the Drill Tool file and the Drill Location file.
To convert the human readable drill header to a NC Drill format, you’ll need to use the following NC Drill lines:
T<toolnumber>C<toolsize>which indicates declares a tool size.
M48which represents that the tool sizes are in inches.
%, which indicates the end of the drill header, and start of the drill coordinates.
To create a tool definition, you simply use a
C command in sequence. As an example this line
T1 0.0300 13
will be converted into
Some tools will provide the drill sizes in different units, typically
mil. To convert
inches, simply divide by 1000. For example, a size of
300 mil would equal
Example NC Drill file
After all conversions are done, you should wind up with a single file in this format.
If your Drill Location file is missing the
% between the drill header, simply add it in.
M48 will ensure that the drill sizes are read as inches.
M48 T1C0.0300 T2C0.0350 T3C0.1181 % T1 X009421Y004444 X007221Y006645 X008715Y005151 T2 X009280Y000526 T3 X011065Y000526 X003475Y002192
In many cases, tools with these issues may also encounter other format errors regarding how to read the provided hole locations.