No doubt the readers of this article will know the results that some of us have arrived at in the last two years. In regard to cutting speeds and feeds there has been and always will be difference of opinion, and it is almost impossible to determine the right feeds and speeds, whether it is for steel or cast iron, and for the operations of planing, turning or milling. The work varies so in different shops; that is, regarding the construction of different pieces, the amount of metal there is to remove from each piece, and how accurately the work has to be done.

There is no doubt in my mind that the makers of high-speed steel have awakened the management of different shops, and it is surprising the amount of work which can be accomplished even with the old machines, with very little redesigning. There is no question but that the machine shops which do very heavy work have not the necessary power for the use of high-speed steels, as the power should be used if the machines are old ones. Referring again to the question of grinding, I wish to state that this is a very important factor in the use of high-speed steels. I have seen much damage to the tools, in many instances making it necessary to treat them over, and as we all know, this takes much time. My recommendation for grinding is to let one man grind all the tools and be responsible for them. When a lathe tool or a machine hand wants his tool ground, he simply gives it to the man who is responsible, and gets another the same size and shape, these being always kept ground and ready for service. In this way the tools are kept uniform and ground alike.

In reference to the amount of work that can be accomplished on different machine tools, the writer finds that the feeds have been altogether too fine on most makes of machines up to the time that they were redesigned for high-speed work. Now it has been demonstrated that high-speed steel has come to stay, and we all know that it works better on roughing work than it does on finishing. If most of the product of the machine department is to be turned, it has come to the point where the majority of work must be ground; and this is the only way to get good and accurate work, especially where the strains of the cut spring the work. Moreover, as it is not necessary to straighten the work to any great extent, it certainly means a great saving, as many of our readers know. The writer is not a builder of grinders, but merely speaks of the saving it has been on his own work.

Below is a fair average of the speeds that most any good make of lathe, planer, drill press or radial, ought to stand when using high-speed steel. Every lathe has a face-plate about the diameter of the swing, or very near that. Take the periphery speed of same by feet minute; the use of a Warner cut-meter will give you speeds instantly. This is one of the handiest little tools that can be obtained, and no machine-shop is complete without it. The speed must be taken with the belt on the largest step of the cone, with the back gears in. The speed of the following sizes of lathes, taken from a large faceplate with the slowest speed, I find to work very well, and considerable saving has been effected on old lathes. Of course, the feeds will have to be determined by the amount of power available:

Larger lathes in proportion.

Planers,

Larger ones in same proportion.

If you have the power in your planers the speeds ought to work on soft steel as well as cast iron.

High speed twist drills, drilling cast iron, ought to drill the following, if you have the power and feeds: 1 /2 in. diam., speed 500 r. p. m., 3 1/4 in deep in one min.

Larger ones in proportion.

These speeds are all based on a periphery speed of 65 ft. per minute. High-speed drills have done somewhat better than this, however; but, taking into consideration the time of grinding, I find that this speed is a good average during a day's work.-"Machinery."