hammer beam vs scantling

hammer beam

noun
  • A member of a kind of roof truss (a hammer-beam truss), so framed as not to have a tiebeam at the top of the wall. Each principal has two hammer beams, which occupy the situation, and to some extent serve the purpose, of a tiebeam. 

scantling

noun
  • Timber in the form of small beams and pieces. 

  • A small, upright beam of timber used in construction, especially less than five inches square. 

  • The set size or dimension of a piece of timber, stone etc., or materials used to build ships or aircraft. 

adj
  • Not plentiful; small; scanty. 

How often have the words hammer beam and scantling occurred in a corpus of books? (source: Google Ngram Viewer )