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It may be that in those comparatively early days of cast steel some makers felt that a different term might be a better selling point. The word survives on a second quality saw of about 1900 (figure 6), added to "Cast Steel", but strictly speaking it is a tautology.
Although after the invention of Bessemer's process all steel (except blister/cementation/shear, much of which went into cutlery) was cast, the word continued to develop, as it were.
Figure 7 is a saw of about 1900, with again an additional word - "Extra" - inserted, one can only assume, for effect. Best is added in a similar way (figure 8), and although this is equally meaningless, there is a potential confusion with an earlier categorization of steel.
In the last quarter of 18th century, there were three grades of steel used by Sheffield toolmakers: cast, best and common. The first is obvious, but there is no documentation of the other two. The sawmaker Joseph Wilson (1768-1775) sold saws of these grades, his most popular being 26 inch handsaw, which cost 5/6, 4/3 and 1/11 each, and chisel marked "best" by Samuel Newbould has also been reported. One can only guess that the two lower grades were blister steel given different degrees of extra treatment to improve their performance. Double refined steelRichard Groves and Sons of Sheffield frequently marked their handsaws (but not their backsaws) with the words DOUBLE REFINED (figure 9).
This term verges on the 'marketing', as it strictly speaking cannot mean what it says: refining steel is casting it, in other words making crucible steel. There are no descriptions of repeated casting of steel, since it was a one-off process (unless of course something went wrong). There are, however, indications that steel was sometimes put twice or even three times through the cementation process. I have not been able to find a description of its being done in England, but Barraclough (Vol 1, p134) quotes a report on a system at Amboise, in France, where in the 1780's blister steel bars were forge-welded in the usual way, but then put back into the cementation furnace for further carburization that made a better quality steel, and for further, third time to make steel suitable for razors. lancets and surgical instruments. As Barraclough says, "the French... were attempting to produce a material of equal quality [to cast steel] by whatever means were available". An alternative explanation is suggested by Ken Hawley, that "Double Refined" might mean that the saw steel was made from double shear steel, that is, blister steel that was forge-welded, rather than cemented, twice. Both were ways of making steel in which the carbon was more evenly distributed through the iron, and therefore more homogenous and reliably better quality. At the risk of making a vague term even more vague, it can be noted that in Spear and Jackson’s 1889 catalogue of steel, saw and other tools at least a dozen kinds of steel are advertised, one being "Best warranted, double refined"; this steel is listed separately from the blister steels, and appears therefore to be a variety of crucible steel, as the Moses Eadon saw in figure 10 suggests.
Silver Steel Elastic Spring TemperFigure 11 is the mark on a brass-back saw of perhaps 1880, and if found on a lot of groves backsaws of that period (but not handsaws, for which they seem to have preferred the words Double-Refined).
It is one of the few marks on saws which illustrate the property of the steel that was more important than anything, once a good quality crucible casting had been made. In the words of an old book on steel "The chief property of steel, and that upon which its value chiefly depends, is known as its temper ability. By heating and cooling it in different degrees and at different rates of rapidity, almost any degree of hardness or softness may be obtained." Having said that, however, the meaning of "Silver steel Elastic spring temper" fades away like Scotch mist. Michael Faraday had experimented in the early years of the 19th century with adding small quantities of silver and other metals to steel in the hopes of improving its properties, but these attempts did not lead anywhere at the time, and "silver steel" on Groves’ backsaws must be put in firmly into the class of advertising: any saw of any degree of usefulness has to be "elastic spring" and the notion that there was any silver in their saws would not stand up for a moment to today’s notions of accuracy in trades descriptions. WarrantedThis word is etymologically the same as guaranteed, but I do not know why it was preferred on tools, unless it might have had overtones of "Royal Warranty". It had, alas, just as little real meaning as some of the other weasel words discussed above. i Ken Barraclough was a metallurgist with the Sheffield steelmaking firm Firth-Brown. His definitive history is Steel before Bessemer, in two volumes, the first on making Blister Steel, the second on Crucible Steel, and was published by Metals Society in 1984.
October, 2005 For further information, contact Simon Barley.
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