Record Detail
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| ov00064 | |
| Tempering a blade at Walker and Hall Ltd., Electro Works, junction of Howard Street and Eyre Street | |
| Sheffield_City_Centre | |
| 1920-1939 | |
| Walker and Hall Ltd. | |
Hardening and tempering knife blades The smither heats the blade in a gas furnace to an approximate temperature of 950 to 1,000 degrees centigrade. It is then quenched in air and the blade at this point is hardened but brittle. It is tempered by heating in a hearth fire at approx. 220 dgrees centigrade. His expert eye enables him to judge the temper of the blade by colour and he knows just when the best combination of hardness and temper have been obtained. The visual degree of accuracy to which the smither works is very fine and is acquired by long experience in tempering blades. After testing for 'spring' the balde passes to the grinding operation.
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