Drill points

[artnmotion]

What is the standard for Drill Points / Drill Point Angles?

Is it required on the drawing per the current standard? I ask as the company I work for wants it shown on the drawing. (i.e pointing to the drill point via note and calling it out as a Drill Point Angle).

thanks.

 

[MikeHalloran]

The 'standard' drill point angle is 118 degrees included.
... but drills are available with other point angles, and there are good reasons to use them.
It only makes sense to specify a drill point angle if you are drilling intersecting blind holes, e.g. in a manifold, and you want to control the geometry of the cavity.

... or if the your boss tells you to.



Mike Halloran
Pembroke Pines, FL, USA

 

[CheckerHater]

ASME Y14.5 doesn’t say much about drill points.

ASME Y14.6 mentions dimension to the drill point depth if necessary.

Nevertheless, if using drill with certain point angle is the only way to produce good part, then there is nothing wrong about specifying it on the drawing.

If it's more like general knowledge kind of thing, it may be appropriate to put it into notes.

 

[MintJulep]

Are you dimensioning a drill, or a hole?

 

[JNieman]

I'm curious what situation would have you calling out the angle of the tool. I could see a situation that MikeHalloran said, but that really shouldn't be stated in that manner. You should call out that no break-through or over-cut allowed past hole intersections, or something. You should leave it up to the manufacturers to decide their tooling, not tell them they have to use a certain tool. Depending on the application, a drill may be the worst choice, anyways. You may prefer a custom-ground tool, or an end mill, or a set of reamers, etc.

It's typically not a good idea to specify the tool to be used. It may -seem- obvious to you that one would use a certain tool but it's rarely the case.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD LT, Autocad Plant 3D 2013, Enovia DMUv5

 

[ctopher]

99% of the time I leave that info off the dwg. Don't need to tell the machinist which drill or drill point to use. It's not needed, unless there is a close tolerance to a near feature.

Chris, CSWA
SolidWorks 14
ctopher's home
SolidWorks Legion

 

[ewh]

You should only specify the drill point if it affects the design. Otherwise it is just extraneous information that, as has been noted, limits the machinist in how to do his job.

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[KENAT]

Simplistically, unless it somehow affects finished functional requirements it probably doesn't belong on the print.

There are some situations where it can matter (we had one here when a part was redrawn and significance of a poorly worded old note about jobber drill wasn't understood) however it's not that common if the drawing is otherwise done well.

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[TWJR]

I see drawings where the draftsman puts flags on the drill notes and note saying "drill point permitted". Are you guys saying that if you see an angle at the bottom of the hole in a cross section, you don't need to do that sort of thing, that it's understood?

 

[KENAT]

I'd say a note about drill point may be appropriate in some situations - so long as it doesn't lead to confusion over the functional depth of the hole.

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[ctopher]

I would not say anything about a drill point unless necessary, as KENAT said.

Chris, CSWA
SolidWorks 14
ctopher's home
SolidWorks Legion

 

[TWJR]

Sounds good to me. Seems like a pain in the butt to have to flag every hole for something that's basically a non-issue.