became generally known to the technical and engineering world, and the highspeed possibilities in the super heating of tungsten steel were clearly seen, manufacturers of tool steel, on both continents, at once began to vie with one another in their efforts still further to perfect the new steels and to increase the range of their usefulness. Within the short time, scarcely six years, since the announcement of the discovery, something like seventy-five brands of highspeed steel have been put upon the market, and their use has become so general as to have a noticeable effect upon the

grain of the early alloy-steels. Though nothing is gained in speed, in wood working, and on the other hand the first cost is many times as great, the wearing quality of these tools is so great that the cost of maintenance in suitable working condition is only from one-twentieth to one-seventieth that for ordinary tools

which is a considerable matter in factories using large numbers of such tools.

It has been pointed out that the new steels require a special treatment in order to develop their peculiar qualities. They may be forged at the customary heats, though generally worked at somewhat

similar oil. It is then so hard that it cannot be cut, and the only way to change its shape is by grinding with emery or similar abrasive wheels. Water must on no account be used on the tool when heated, for it ruins it instantly.

For some purposes, as where the cutting edge is necessarily somewhat acute, a tool thus hardened will not answer. It is too hard. That is, it is brittle, and crumbles away at the edge when set to work. There is no sufficient backing below the edge to support it under the tremendous pressures developed in cutting metals, and it gradually breaks away. To avoid this it is necessary to anneal the tool by reheating until it shows a tinge ranging from dark straw color to a slight green, the degree of heat depending upon the kind of service required; and then allowing it to cool very slowly in the air. A tool thus "tempered" or "drawn" is no longer of glassy hardness, but has become much tougher. It is

therefore unable to work so rapidly or so heavily; but its acute edge does not break down.

The thing in the way of running ordinary tools at high speeds, as already hinted, is the heating and consequent softening of the cutting edge by the excessive friction of the chip upon the tool while being separated from the mass and bent out of the way. Alloy-steels are not, within certain limits, thus affected. Indeed they seem almost to require abuse in order to develop their highest capabilities. Generally such a tool will not. work to the best advantage until it has been run a little while and warmed up, which is to say, until it has become pretty hot. The speed at which high-speed steel tools can be run and the size of chips they are capable of removing are indeed marvellous, compared with former performances. For whereas an ordinary tool is capable of cutting steel at the rate of, say, thirty lineal feet of chip per

minute, the average in a well managed machine shop being not much in excess of twenty feet, an alloy-steel tool on a similar job cuts as high as one hundred and fifty and even more, as a regular performance. Though about five times as great as under the old regime, and perhaps twice as great as the average in ordinary shop practice with this kind of tools, this is by no means the limit of speed and endurance. In experimental tests it has been demonstrated that such tools could be worked up to a speed of more than three hundred feet per minute, for short runs. That is, the tool could be speeded up until the point become red hot and the chips were a deep blue color from the heat generated! Of course a tool could not be worked continuously at any such speed, for like a carbon steel one, it softens when red hot, and the edge begins to rub away rapidly. In many shops, however, it is customary to run the tools as speedily as possible while still keeping the temperature low enough not to show much color at the

point. Even at such a rate, when cutting ordinary steel even, the chips frequently come off a deep blue.

The pressure exerted in cutting large steel chips is of course tremendous, amounting frequently to many tons. To resist such tremendous stresses not only the tool but the machine in which it is used must be very strong and rigid. The machinery in use up to five years ago, heavy and solid as it seems to the casual observer, is quite inadequate to the task set by high-speed tools; and where this old machinery is still used with the new tools, only a portion of the possible efficiency is obtained. To meet the new requirements designers and manufacturers of machine tools are producing them much heavier and more powerful than ever before.

Besides the fact that the new cutting tools require, for the attainment of their highest efficiencies, a new type of machine, the cost of the alloy-steel itself deters many from its larger present use. Tungsten, molybdenum, and the other

steel hardening metals are comparatively rare, and are correspondingly costly, the price at present ranging from about forty cents to six or seven dollars per pound. Not only this, but special this, but special processes are used in the manufacture of the steel to secure perfect homogeneity and uniformity. While, therefore, ordinary carbon tool steel can be had for something like two cents per pound, high-speed steel sells for sixty-five to seventy-five. Even at this price, however, considering what it does, and the savings it is capable of effecting in many kinds of cutting jobs, it is by far the cheaper in the end. In a certain case (extreme, of course) it has been found that a small high-speed tool costing about eight cents has made it possible to dispense with the labor of one of three men employed on a job, and thus to effect a saving of the man's wages in connection with the manufacture of that particular piece. If such a saving were possible in all cases, the industrial revolution certainly would be not only at hand, but very quickly accomplished. As a matter of fact, however, in most manufactur

ing processes involving the machining of metal parts, the actual time required for cutting is but a part, sometimes relatively insignificant, of the whole time necessary. So that the new tools when put to allround work do not effect economies such as would be possible were most of the operating time devoted to cutting. Nevertheless it is a rather rare case where the cost of production could not be cheapened in the tool maintenance account, even if not in the actual time and labor saving.

The new high-speed steels are indeed a marvel; but they are as yet only in the infancy of their development and usefulness. Only a bare six years old, they are, but they have already had a marked influence upon productive industry, and nothing is at present more evident in the metal working trades at least than that an actual revolution is in process-not so rapid indeed, relatively, as the performances of the steels themselves, but nevertheless in a way still comparable to itand in a fair way to be accomplished within a very few years. In fact, every day is seeing a new stride toward it.

Expect success.

Do the things you are afraid to do.

Don't flirt with your business, for two can play at that game.

Happy is the man who enjoys the work that he must do.

Yesterday cannot be recalled; tomorrow cannot be secured; today is thine.-Emerson.

Will a lonely dog follow you?

Books are friends that should be cut.

¶ If you would make your life easy, make it hard.

¶ If work was as easy as lying, everybody would be busy.

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