摘要 |
<p>The knob is made from ceramic and is cast with a central hole (3). It is square and has rounded edges and corners. The bore is stepped to take a stepped plug (5). The plug is held in position by a layer of adhesive. The plug has a parallel bore (6) to take the holding down screw. The plug may be made from metal. The clearance between the bore (3) and plug (5) allows for centring the knob on the tap.</p> |