The measurements above are for piece (A), the opening diameter of piece (A) is 9.9cm. Piece (B) measurements are: H: 9.1cm, D: 10.5cm, the diameter of the opening: 9.2cm.
Bibliography and Bibliographic Notes
Book: Salaman, Raphael Arthur. 1990 Dictionary of Woodworking Tools c. 1700 -1970 and tools of allied trades.