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Dimensioning Chamfer/Countersink?


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Posted

How would I go about dimensioning this chamfer/countersink for this tube?

 

I would really appreciate the help.

 

[ATTACH=CONFIG]40288[/ATTACH]

Posted

Is this the correct way to dimension the highlighted detail?

 

 

[ATTACH=CONFIG]40289[/ATTACH]

Posted

Do not dimension to the drill point - that is an artifact of the tool. It is not the feature. And it is not a 45° chamfer. (drill point is actually 118° included angle for standard drill)

Dimension the cylindrical depth in one view only (not both) I would do in the end view with the hole thread note.

 

So remove both hole dimensions from the side (hidden) view.

In addition to drill depth add the tap drill depth.

Avoid specifying tap drill depth the same as the hole depth - the machinist will be very mad when taps break as a result.

 

The hole drill depth should be at least 3 or 4 pitches deeper than the thread pitch (4*1/18 in this case). On a part like this I would go a bit deeper.

 

I have not mentioned how to specify a Countersink feature dimension as I don't see a countersink in your views.

It would be good to countersink though and the machinist is going to do this anyhow with a centerdrill before drilling the hole.

Posted
Do not dimension to the drill point - that is an artifact of the tool. It is not the feature. And it is not a 45° chamfer. (drill point is actually 118° included angle for standard drill)

Dimension the cylindrical depth in one view only (not both) I would do in the end view with the hole thread note.

 

So remove both hole dimensions from the side (hidden) view.

In addition to drill depth add the tap drill depth.

Avoid specifying tap drill depth the same as the hole depth - the machinist will be very mad when taps break as a result.

 

The hole drill depth should be at least 3 or 4 pitches deeper than the thread pitch (4*1/18 in this case). On a part like this I would go a bit deeper.

 

I have not mentioned how to specify a Countersink feature dimension as I don't see a countersink in your views.

It would be good to countersink though and the machinist is going to do this anyhow with a centerdrill before drilling the hole.

 

If it's not too much trouble, can you show me an example?

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