Size of the screw hole

[zhenpengD5CN6]

I want to create a screw hole for M2.5 screw on my model. Thankfully Fusion 360 provides an option for M2.5 screw hole. But the diameter is a little off from my measurements. A M2.5 screw I had measures 2.4 mm at the max diameter and 2.2 mm at the minimum diameter. But Fusion 360 only provides a diameter of 2.076 mm. Which one is the correct M2.5 screw size?

Thanks

[LibertyMachine]

That is the tap drill size. If you are looking for a clearance hole, change the selections in the hole dialog

[vgomasjaya]

why the clearance hole doesn't have hole? because I want to make a thread hole, but the tapped hole does not suit with my bolt

[seth.madore]

I'm not sure I understand your question. Do you have photos or the Fusion file to show what you are referring to?

[vgomasjaya]

I mean, example I have M2 screw (where the diameter of the thread is 2 mm).... So how can I make hole that have thread that suit with my M2 screw? Because tapped hole in fusion360 have only 1.6 mm....

[seth.madore]

What you are seeing is the minor diameter of the thread. An M2 requires a drilled hole of 1.6mm.

If you had a hole that measures 2mm, there will be no material for threads.

Are you designing something or trying to machine it? Is this 3D printing related?

[vgomasjaya]

oooo okey thank you... yes for 3D printing

[seth.madore]

What do you have for a printer, and is printing threads the best route? An M2 is quite small, and given filament choices and accuracy, I'd be more inclined to go with a press-fit captive nut (in steel) or similar

[vgomasjaya]

I use steel screw, I only print the hole....

Btw for tapped hole, I'm still confuse about diameter that displayed in this picture...

1.6 mm is the major diameter or minor diameter?

[seth.madore]

Alright, let's pause for a moment:
Are you printing a hole that's large enough to accept an M2 thread dropping in, so there are no threads in the hole, just a smooth wall (well, as smooth as 3d printing allows for)? If so, you just need to use the Hole tool and define this:

 

[vgomasjaya]

no, I want thread hole for M2, but in tapped hole, the diameter is 1.6 mm, not 2 mm 😞

[seth.madore]

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@vgomasjaya wrote:

no, I want thread hole for M2, but in tapped hole, the diameter is 1.6 mm, not 2 mm 😞

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It seems that we're misunderstanding each other.

If you are printing a hole for an M2 and that hole is going to be threaded, the hole diameter IS going to be 1.6mm, as that is the "minor" diameter of the hole.

If I had a block of metal and I wanted to tap the hole, I would use a 1.6mm drill, drill the hole and then tap/threadmill it.

If I wanted to drop an M2 screw into the hole and use a nut from the opposite side, I would use the Hole Command and either define the hole size I wanted or set it to "Clearance" and define the thread size.

All that said; printing an M2 thread is not going to be very strong or accurate. There's also a likelihood that the screw won't even go in, due to material shrinkage. 

[vgomasjaya]

ok thank you!

[jeffescott]

The drawing in message 9.  Shows the outer diameter has 1.6 mm

the thread indicatios in the middle cause the confusion

[seth.madore]

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@jeffescott wrote:

The drawing in message 9.  Shows the outer diameter has 1.6 mm

the thread indicatios in the middle cause the confusion

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And that's what it should be showing, as an M2 threaded hole is not going to measure 2mm, but 1.622mm

[jeffescott]

You miss the point.  
The thread symbol shown inside the screw have large line and a small line.  That would indicate the major dia is  referenced not the much minor dia.

Simple answer remove thread symbol from message 9.  Or show threads a dimension correctly.

I got it but someone struggling with the language will rely more so on visual clues….hence the problem.  
Fusion has more the a few imprecise usages