Drill Size Incorrect for Tap Size
Drill Size Incorrect for Tap Size
(OP)
Could anybody link me to a site that may be able to fix the drill size callout problem. I have lived with this for 2 versions now and was hoping that when you invest good money in SW they could get drill sizes correct. (Basic Tap Sizing from a STARRETT drill chart) Examples the 1/4"NC and 8-32 give incorrect drill sizes. Is this a setting problem? I shouldn't have to modify operating files of the system to get this to display correctly?(callout.txt)

TTFN
Captain-Caveman

TTFN
Captain-Caveman






RE: Drill Size Incorrect for Tap Size
1/4"-20 gives Ø.201"
#8-32 gives Ø.136"
Both match Cleveland & Unbrako Tap Drill Charts.
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RE: Drill Size Incorrect for Tap Size
I guess I'm in between the 2 of you, I know the decimal size is right, but I would like to see SW give the number or letter size of the drill instead of the 3 place decimal. I know this usually gets everyone started on drafting standards, whats right, whats wrong, what a machinist needs, but it comes down to it that our prints have shown the number or letter drill for a long time and the guys in our shop like that.
mncad
RE: Drill Size Incorrect for Tap Size
1/4"-20 = Ø.201"
#8-32 = Ø.136"
everything matches the charts listed in Machinery's Handbook
RE: Drill Size Incorrect for Tap Size
Look in the Machinery's Handbook. They vary the tap drill size with the depth of the hole. I would not be sure the machinist does not vary it with the material.
This was discussed at length in Thread559-86931.
JHG
RE: Drill Size Incorrect for Tap Size
(.136" for 8-32) but to get to this I have to change the individual properties of the callout to decimal @ 3places.
I work at a welding/fabrication shop and everything is deemed inches usually toleranced to 1/32". Anymore would be a waste of time. We are not building aircraft components here-(Depth to drill size variation has no bearing.) Maybe it is something that can be set in the template or defaults so it reads #29 drill for an 8-32 tap.
It seems to me the callout is driven by the linear drawing unit default of the drawing.-(1/32") in my case. That is why the drill size rounds down to a callout of 1/8"
RSVP / TTFN
Captain-Caveman
RE: Drill Size Incorrect for Tap Size
RE: Drill Size Incorrect for Tap Size
Giving a specific drill size is a work instruction not a quality requirement of the part. The Drawing should state the requirements of the part. I am sure the guys in the shop like it but I am also sure they would like it if you glued the correct drill to the drawing. The problem with stating a specific Drill is that you are creating an assumption that you know what type of tap is going to be used, roll taps for instance may require a different drill size. You can achieve a 1/4-20 thread with a variety of tools, if the 1/4-20 thread is the requirement that is all that needs to be and all that should be stated on the drawing.
In closing to answer your questions, you did pay good money for something that does work properly, it does not work the way you wish it too but it does work properly by industry standards. If you can modify a system file to add the custom non-standard information you wish then all the more power to you and good for SolidWorks for giving you the opportunity to do it.
RE: Drill Size Incorrect for Tap Size
-tap drill sizes default to document units so if you've got a metric tap on a fractional imperial drawing, your tap drill will be in imperial fractions
-drill depth does not always show "Thru All" when it should - even when you define the hole wizard hole as though all, sometimes the drill depth still comes up with a value
RE: Drill Size Incorrect for Tap Size
I can remember using Cadkey Version7 and they had it working right back then. If I can get the software to not even show the drill size I would be happy with that.
ttfn
CaptainCaveman
RE: Drill Size Incorrect for Tap Size
Making the best use of this Forum. FAQ559-716
How to get answers to your SW questions. FAQ559-1091
Helpful SW websites every user should be aware of. FAQ559-520
RE: Drill Size Incorrect for Tap Size
ttfn,
CaptainCaveman
RE: Drill Size Incorrect for Tap Size
The option to get rid of the drill callout:
The default formats for the Hole Wizard types are stored in installation directory\lang\<language>\calloutformat.txt. A second file, calloutformat_2.txt, is a simplified version this one does not put the drill size in a tapped hole note. You can edit either file. If you want to use the second file, you must rename the file to calloutformat.txt, which is the file name the SolidWorks software references so first rename the original to retain it.
You can set the location of the default folder for Hole Callout Format File in Tools, Options, System Options, File Locations.
RE: Drill Size Incorrect for Tap Size
If that does not work, select the callout and go to it's properties. Uncheck "use document's units" and then select the units... button right above.
These options should solve the rounding error.
RE: Drill Size Incorrect for Tap Size
C:\Program Files\SolidWorks\lang\english\calloutformat.txt
A macro could probably be written to scan a drawing and set the drill sizes to three decimal places. A more aggressive project would be to replace the dimension with a drill number or letter.
RE: Drill Size Incorrect for Tap Size
TTFN
CaptainCaveman
RE: Drill Size Incorrect for Tap Size
Making the best use of this Forum. FAQ559-716
How to get answers to your SW questions. FAQ559-1091
Helpful SW websites every user should be aware of. FAQ559-520