What dimension does rebar have?

[s37632]

The son-in-law bought 10 mm rebar to be used for building a simple fence. He used concrete bases with post shoes and 4" treated fence posts.
Drilled holes in the posts with a 12 mm wood drill and was supposed to slide the rebar into these. Almost impossible without damaging the posts, gave up after forcing it through a hole with effort. What dimension does a 10 mm rebar have if it doesn't go through a 12 mm hole in a wooden post?
What's wrong, have we thought wrong?

 

[gusvo085]

10mm is 10mm... are you sure you didn't get 12mm iron?

 

[Stefan_E]

It is the core of the rebar that is 10mm in diameter. Then the ribs protrude beyond this, measure where the ribs are.

 

[s37632]

Used wood drill 13mm then it worked.