carriage bolt

from WordNet (r) 3.0 (2006)

carriage bolt
    n 1: a roundheaded bolt for timber; threaded along part of the
         shank; inserted into holes already drilled

from The Collaborative International Dictionary of English v.0.48

carriage bolt \carriage bolt\ n.
   a type of bolt threaded only at the end opposite the head,
   used mostly for fastening pieces of timber together, and
   inserted into pre-drilled holes.
   [PJC]