holes.txt
holes.txt
(OP)
Is there anywhere I can download a holes.txt file with many non UNC UNF UNEF inch threads?
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RE: holes.txt
We've just been going thru modifying ours to add some UNS etc.
You can set up an excel spread sheet to calculate the values for you and get them out almost in the right format for holes.txt. Just takes a bit of thought.
There are some good sites to calculate the info you need if you don't fancy the excel sheet.
Post if you need them and I'll try to dig them up.
RE: holes.txt
I think there is no need to have the values accurate. The rule
is quite simple:
nominal dia > internal minor diameter >= external minor diameter
that's all. I didn't find the values for some special threads so I
rolled my own which looks like this and works well (metric):
6.0; 4.800; 4.800; BA0
3.97; 3.157; 3.157; ME 5/32"
Major/Minor will be used to show the 'cosmetic' threads in a draft.
The nominal diameter will be used to pick up the matching thread(s)
for a bolt to populate the pull-down. Not even the fastener system
uses the minor/major values: it will put an M10 bolt of any
pitch into an equal sized (threaded) hole.
dy
RE: holes.txt
The minor diameter on internal threads somewhat affects physical properties (mass and volume), but not much considering the number of significant figures. The cosmetic thread portion on an internal thread may be an issue if you are placing a bolt really close to an edge. But, if you're that close, you perhaps should rethink your design.
To fill in the blanks for holes not in the holes.txt file, I use the machinery's handbook or the appropriate ISO/ASME standard. Any holes not listed in the standard, I just interpolate to get me close.
--Scott
For some pleasure reading, try FAQ731-376
RE: holes.txt
You obviously haven't heard the complaints about the fact that the default holes .txt changed from having the tap drill dia to having the minor dia at some point.
Lot's of upset people apparantly.
Having correct minor dia can be useful. If your threaded holes ever serve dual duty as both threaded and clearance holes (eg you put a dowel pin or something thru the hole before inserting a screw) then I believe having correct minor dia will help with interference checks. For most people it's probably a minor consideration.
I'm always loathed to deliberately put incorrect representative information as at some point someone will try and use it as true data. If it's at least approximately right you get less problems.
I'll try and put some of the links/equation in a future post.
RE: holes.txt
especially in Europe/Germay the drill size will not be given for
a threaded hole just specify it as say M10 that's it. The drill size
is also just a ball park figure because it depends on the material
and the desired flank engagement.
The values shown in may sample are preliminary just to please
SE, when I get some data they will be changed and the hole.txt
get's an update.
Sure in a future the minor/major values might be used but currently
not. If the kind of business requires these values to be exact OK
then there is a must otherwise an approx. value will do
Threading with CNC might require it but what I've worked with so far
there was no need for the values
But everyone should do it like he wants it to be
dy
RE: holes.txt
According to ASME Y14.5 and the standards I used to follow in the UK you shouldn't normally call up the tap drill, just the thread.
Also 99% of the time for most people putting values like you have probably isn't an issue.
http://www.boltplanet.com/default.asp
This gives figures for non standard UN screws which I believe talktosocks may have been after.
Can't find the spreadsheet right now.