Hardening and Tempering Engineers' Tools by G. Gentry

Description

The efficiency of cutting tools employed in engineering and other crafts depends very largely on their correct heat treatment. The use of carbon steels is still predominant and, although the methods of hardening and tempering such tools is relatively simple and straightforward, there are many users of these tools who run into difficulties when attempting to harden and temper them. In the past, the methods employed in these processes have often been governed mainly by rule of thumb, and experienced tool makers have often evolved individual methods which have been in some cases closely guarded as trade secrets. Reliable practical information on the subject has been difficult to obtain. There is, however, no reason why even the novice should not be able to harden and temper tools quite successfully by adopting simple methods which can be applied without the need for elaborate equipment. Since the original edition of this book by George Gentry was published over 30 years ago, several later editions have included information on current trends in tool technique and metallurgy to keep it fully up to date with modern practice, while still concentrating on basic requirements of the small Workshop. In the present edition the chapter on case-hardening has been completely re-written, with more fully detailed description of the latest processes, materials and equipment; also new information on gas hardening, nitriding and flame hardening. Other additions include reference to methods of measuring hardness, and details of gas and electric furnaces of a type suited to the small workshop, technical school, laboratory or factory.