Correctly shaped diamonds can be gripped in a steel shank and used as lathe-cutting tools. They have four attractions, namely (a) they are so hard that they can attack the hardest of modern alloys, (b) they retain their sharp edges for very long periods of intensive use, (c) they are capable of producing superfine finishes, (d) they can attack all sorts of 'difficult' objects which give ragged results with conventional steel- or carbide-tipped tools. Diamond lathe-cutting tools are surpris¬ingly ubiquitous in the range of materials they can attack. One can turn and drill, on the one hand, soft metals like aluminium, silver and gold, and on the other, hard steels and carbides. Strangely enough they are admirable for soft rubber, such as that for the production of rollers for typewriters or printing machines, they are used for the turning of plastics, both soft and hard, and even for the processing of compressed paper rolls. Also check custom wedding bands. They are used extensively in the jewel trade, for turning watch parts and for smooth mirror-finishes on gold and silver. Equally, they are used widely in the automobile industry and can produce soft silky finishes on complicated alloys such as Babbitt metals, used for bearings.
It is necessary to set the cutting tool in correct orientation to present a hard edge and avoid cleavage direction, and this the manufacturer must do, yet the operative needs to use care. A damaged or blunted diamond (incorrect use. can chip edges) can be re-polished (by skilled diamond polishers only, of course) so is by no means a total loss. Lathe-cutting diamonds can be fastened into steel shanks by 70.
