Hole tool - clearance hole standards

[BuddyHudson]

To all,

I have an engineer that is asking about the clearance hole diameter values that are pre-filled in the hole tool based on screw size nominal. Does someone know what standard these follow? The values in the hole tool follow the machinist handbook, but they do not agree with the ANSI/ASME values? I would appreciate your feedback....

Buddy Hudson

[dschenken]

Ultimately the size of the hole needs to account for the hole diameter tolerance, the straightness, perpendicularity, and the location tolerance. It's a little ignorant for there to be national standard on just one aspect.

It surprises me a little if they don't match, but I've never used the ANSI/ASME B18.2.8. I have used Machinery's Handbook and see no need to spend $35* for something covered in a dozen pages of a more comprehensive book.

*http://webstore.ansi.org/RecordDetail.aspx?sku=ASME+B18.2.8-1999+%28R2005%29

[TomD.inPDX]

I think this is one of those cases where the tools are given for you to implement to your desired standards.

I don't trust anything PTC provides without vetting it for myself.