Drill and Tap; and calloutformat.txt (Part 1)

This entry is part 1 of 4 in the series Hole Callouts

Sooner or later, the topic of how to callout a threaded hole comes up in pretty much everyone’s career in the Mechanical Engineering field.  I’ve seen the nature of those discussions be straight forward, but I’ve also seen angst riddled arguements.  Though this isn’t a SolidWorks specific topic, it is important to its users. This is because SolidWorks specifies hole callouts differently in different scenarios.

The conventional rule (within ANSI Inch) is that a threaded hole should be called out as a leadered note showing its nominal drill size and depth on the first line, and the thread size, threads per inch, thread series designation, thread class and thread depth on the second line.  This is common practice, so most people are comfortable using it.

Example (without use of symbols):
2X .190 DIA .190 DEEP
8-32 UNC-2B .164 DEEP

Of course, this method has flaws, which I’ll get into later.

I’ve seen two extremes as well.  At one extreme, the threaded hole callout has the actual drill bit size listed in addition to specification for the tap and drill.  I gather it would look something like this:

2X .438 DIA .25 DEEP WITH 7/16 Q DRILL
.438 UNC-2B .375 DEEP

Of course the basic flaw with adding the drill size is that this is a specification of process, which is generally disallowed by ASME Y14.5M-1994.  It is equivalent to having the note “FORM THIS PART WITH LATHE MODEL XYB”  or even, “JUMP UP AND DOWN THREE TIMES AND SPIN IN A CIRCLE BEFORE USING THE MILL TO CUT THIS HOLE”.  Hyperbole aside, this practice is not appropriate.

On the other end, one might find a hole callout that simply states the thread size, such as “TAPPED HOLE”  This is a bad case of under-specification.  I haven’t seen this method often on formal drawings, but it is very common on preliminary sketches.  There just isn’t enough information.

What is just-enough-information for a threaded hole callout?  Well, this answer is easy.  Thread size, threads per inch, thread series designation (sometimes considered optional), thread class, thread depth, and sometimes drill depth or end condition.  The “nominal” drill diameter isn’t actually needed.  There’s several flaws with including the drill diameter.  First, the actual drill diameter is not based on the callout, but rather the thread itself.  It is over-specification.  Second, drill diameter is stated as a dimension, so it is not nominal.  Because of this, the standard drawing tolerance must be applied to that dimension.  Again, this is over-specification because the thread has its own tolerance for its final size.  Simply by stating the thread class, its tolerance is called out.  Third, because of these other points, specifying the drill diameter is actually a specification of process.  Given all that, I always callout a threaded hole as so:

2X 8-32 UNC-2B DEPTH .165

In the rare event that drill hole depth or end condition is necessary to call out, then simply state that specification in the callout, or show it dimensionally on the drawing view itself.  How this relates to SolidWorks and the calloutformat.txt file will be discussed in Part 2 of this article.




How to add Watermark to SolidWorks Drawing (with linked value)

How to add a Watermark to SolidWorks Drawings
By Matthew Lorono
For whatever reason, watermarks are sometimes necessary, even on drawings. Since SolidWorks has no watermark feature, and does not allow the user to change the order of certain drawing entities, a workaround is necessary. Here the most effective and powerful method useful for Drawing Templates and Sheet Formats.
1. Open the drawing.

2. Create a drawing layer by choosing the layer icon.

Layer Toolbar

3. Change the layer name and description to something identifiable.Then click on the color block in the Color column and choose a very light color.Select OK.

Layer Window

4. Goto pulldown menu File and select Properties.
5. Add the property Watermark.As a place holder, give this property the value of “PRELIMINARY” or something similar.

6. Edit Sheet Format.

7. Use Annotation Note to create and place the entity that will become the watermark.

8. Edit the properties of that Note to adjust its font, angle, size, etc as desired.Then, link the Note to the custom property Watermark, as shown in the figure.Select OK.

Annotation Note Properties Window

8. Change the layer of the Note to the newly created layer.

**UPDATE: New functionality in SolidWorks 2013 makes steps 9 and 9.5 no longer necessary, please see this article for details: Sometimes it’s the little new things – Watermarking **
9. Right Mouse Button click on the Note and select Make Block and accept.

9.5. Due to some funky behavior that I’ve discovered by SolidWorks when loading a watermarked template into an existing drawing, I’m adding this one step: Once you make the block, change the layer of the block to the same layer you set for your Note.
10. Save the Sheet Format (under pulldown menu File and select Save Sheet Format).

11. Edit Sheet.The Note will now appear underneath all other objects on the Drawing Sheet.

12. Save this document as a Drawing Template (under pulldown menu File and select “Save As”, then change Save as type to “Drawing Templates”).
This creates both the Drawing Template and Sheet Format with an embedded watermark.To change the text of the watermark in any drawings that use the Drawing Template, simply go back to Files>Properties, and edit its text value.To remove the watermark, simply replace the current value with a space.These instructions are geared towards SolidWorks 2007 or earlier. SolidWorks 2008 or later instructions will be similar, though how to access some of the functions may have changed.

Create a SolidWorks Drawing Watermark

For whatever reason, watermarks are sometimes necessary, even on drawings. Since SolidWorks has no watermark feature, and does not allow the user to change the order of drawing entities, a workaround is necessary. Here’s a method I recently discovered.(I am currently using SolidWorks 2007 SP3.1.)

 

  1. Open the drawing.
  2. Edit Sheet Format
  3. Use Annotation Note to create and place the text that will become the watermark.
  4. Edit the properties of the Note to adjust its font, angle, size, etc as desired.
  5. Highlight the Note and change its color using the Line Color function.For best results, assign a very light color to the Note.
  6. Right Mouse Button click on the Note and select Make Block and accept.
  7. Edit Sheet.

 

The Note will now appear underneath all other objects on the Drawing Sheet. This tip is based on the SolidWorks Forum discussion which can be found here:http://forum.solidworks.com/forum/messageview.cfm?catid=6&threadid=1989&enterthread=y

*UPDATE*

I have written an article detailing a more advanced method that will link the text of the watermark directly to a custom property here: Create a SolidWorks Drawing Watermark (with linked value).

>

UPDATE for SolidWorks 2013

SolidWorks 2013 now has the ability to set any annotation note on the sheet format to appear underneath all drawing elements to act as a watermark.  The method mentioned above is no longer necessary to achieve the desired results. Please see SolidWorks 2013 What’s New – Display Note Behind Sheet.