Tapped hole vs hole

[guaracas]

Hello,

In the left I use tapped hole and in the right I use hole and tread function.

I do not understand why the tapped hole is smaller than the bolt.

Thank you 

[gmwi · Accepted solution]

The default setting for threaded holes is to show the "tap drill" size which is always smaller then bolt hole.

[JDMather · Accepted solution]

You did not Attach example *.ipt file here?

Clearance Hole should be larger than the fastener.

Tap drill Hole for thread should be smaller than the fastener (to have material for cutting the thread).

Ø.5 would be too small for a 1/2-13 thread as there would be no material to cut the thread (the fastener would simply spin in the hole).

[pcrawley · Accepted solution]

Also worth noting is that if you use the Hole feature followed by the Thread feature - the hole is drilled to the size you specified (12.7).  If you add the thread as a second feature, it doesn't reduce the size of the hole to the correct tap drill size.

Using the Hole feature alone to create the hole and thread, Inventor uses the correct tap drill size for the hole - which is critical if you don't want the bolts to fall out 😉

You can edit all the hole/tap drill/thread sizes in the Excel spreadsheets in your \Design Data\XLS folder.