A plate holder for displaying an ornamental plate on a wall surface has three radial arms joined in a common center and spaced at fixed 120. degree. angles from each other to form a rigid planar structure. Each of the arms has a flat rear surface which together define a back plane such that the holder may be hung flat against a wall. The outer end of each of the arms has a plate retaining portion which extends over the rim to secure retain the plate between the arms. At least one of the plate retaining portions is adjustable along a radial direction to permit insertion of the plate within the holder and also to accommodate plates of different diameters.
A three-jaw chuck of a lathe is adapted to rectangular or square-shaped work pieces by a U-shaped adaptor placed on one of the jaws. The adaptor may be adjustable as to the distance between the jaw tip and the support surface for the workpiece. Alternatively, a set of adaptors of differing thickness can be provided for purpose of selection on a case-by-case basis.