topic Re: Hole with a rectangular counterbore followed by a countersink in Inventor Forum

Hole with a little cylindric boring followed by a countersink

roberto_fantini — Thu, 20 Mar 2025 15:44:15 GMT

In the hole creation options, I believe there has always been a missing feature: the ability to create a hole with a little cylindric boring followed by a countersink, as shown in the image.
Neverthless this is a very common machining operation.

Currently, to achieve this, I have to create a hole with a cylindric boring and then manually add a chamfer

Please vote if you agree!
I think the solution suggest by Francobecerica is the best

Re: Hole with a rectangular counterbore followed by a countersink

francobecerica — Tue, 18 Mar 2025 18:17:29 GMT

Good idea Roberto! Making a lowered floor is equally boring, one dimension would be enough, it is much faster.

Re: Hole with a rectangular counterbore followed by a countersink

jtylerbc — Tue, 18 Mar 2025 18:18:06 GMT

I'm a little confused. You mention "rectangular" twice, but the only thing in your screenshot that looks like a counterbore is called out with a diameter, and therefore seems to be round.

If I'm understanding the picture correctly, this is something we could use at my company as well. But the difference in how you describe it and what your picture shows gives me some doubt as to whether I'm understanding correctly.

Re: Hole with a rectangular counterbore followed by a countersink

SBix26 — Thu, 20 Mar 2025 00:42:18 GMT

I'm reading it as the shape of the section. In English, though, a counterbore is straight sided, so it is redundant to specify its "shape".

I think the easiest way to accomplish this in Inventor is to create the blind, flat-bottom hole first, then add a countersunk hole with the countersink diameter equal to the blind hole diameter.

That takes care of the modeling, but the drawing's hole note is not simple, either.

Sam B

Inventor Pro 2025.2.1 | Windows 11 Home 24H2

Re: Hole with a rectangular counterbore followed by a countersink

WP_Australind — Thu, 20 Mar 2025 04:30:05 GMT

Do you mean a hole for this type of bolt?

See attached.

I would use the Countersunk Hole method as above then manually create the square section.

It would be advisable to check with whoever is going to machine it on how they are going to do it first.

Re: Hole with a rectangular counterbore followed by a countersink

roberto_fantini — Thu, 20 Mar 2025 07:33:59 GMT

ou are right. I apologize but I do not know English well and I cannot find a translation in technical English adequate for what I want to say. If you can give it to me, I will gladly replace it. The image however explains exactly what I want. A short cylindrical bore and then the flare. Francobecerica has hit the nail on the head in my opinion.

Re: Hole with a rectangular counterbore followed by a countersink

roberto_fantini — Thu, 20 Mar 2025 07:41:15 GMT

Hi, no: I mean a hole with a short cylindrical bore and then a countersink, like in the image from jtylerbc

Re: Hole with a rectangular counterbore followed by a countersink

WP_Australind — Thu, 20 Mar 2025 07:44:37 GMT

I've only ever used these type of bolts on a leading edge of a sacrificial blade for a loader bucket.

The square holes were laser / water jet cut, then the cone counterbore was machined.

I.E. the clearance hole for the circular shaft / thread was not required.

Re: Hole with a rectangular counterbore followed by a countersink

roberto_fantini — Thu, 20 Mar 2025 07:50:48 GMT

I edited the text. I hope it is clearer now. Thanks for the note

Re: Hole with a rectangular counterbore followed by a countersink

jtylerbc — Thu, 20 Mar 2025 15:27:53 GMT

Yes, that's clearer. In English, just the word "counterbore" would have been enough, so the extra word had me uncertain. We are actually talking about the same thing. My company uses holes like this sometimes, and we currently use the method @SBix26 described using two hole features. It would be nice to have an easier way to model them (and annotate them on the drawing).

I've considered making an iFeature for it, but we don't use them enough for it to have annoyed me to the point of doing that (so far).