Cochoirs or cauchoir(e)s
The 'cochoir', also spelled 'cauchoir(e)', is a specialised form of billhook used in the 'tonnelleries' or cooperages of France. It appears never to have been used in Britain, but is probably common elsewhere in Europe...
The closest British tool in appearance and, to a certain extent, function is the slater's axe (zax or saxe) - both may have some common ancestry.... or it may be a case of parallel development - i.e the shape developed as the most suitable for the task.
The Cochoire (or Cauchoire) as used in the tonnelleries of France
A brief study of a little known type of billhook used in the cooperages of France
The cochoir or cauchoire.pdf
Adobe Acrobat document [1.8 MB]
A brief study of a little known type of billhook used in the cooperages of France
The cochoir or cauchoire.pdf
Adobe Acrobat document [1.8 MB]

A plain square bladed French 'cochoir' with a single bevelled cutting edge and a cranked, or offset, handle.

A slater's axe or 'saxe' - similar in shape to the 'cochoir', but with a spike to pierce the slate for the nail hole, and a more obtuse bevel to the blade.
