P

Torch-Cutting of Stainless Steel
Made Possible by New Equipment

RODUCTION flame-cutting of stainless steels is a problem that has baffled engineers for years. It has now become posIt has now become possible through a process developed jointly by the Air Reduction Co., 60 E. 42nd St., New York City, and the Rustless Iron & Steel Corporation, Baltimore, Md. Up to this time, one of the limiting factors in the economical fabrication of stainless steels was the lack of an efficient production method for cutting these steels with the oxy-acetylene torch. The very elements that give stainless steels their desirable properties produce oxides when attempts are made to cut them with conventional oxy-acetylene cutting equipment, reducing the operation to a slow melting-away process.

With the introduction of the Air Reduction Co.'s Flux-Injection cutting equipment, stainless steels containing as much as 50 per cent of alloying elements can be cut as readily as ordinary steels. The method has been developed for use with any Airco standard cutting machine equipped with a modified conventional machine

cutting torch and a standard tip. For handcutting, a torch adapted for use in cutting stainless steel is also available.

The principal factor in the development is the use of a flux in powdered form which is automatically applied in the cutting flame. The FluxInjection unit weighs about 75 pounds when fully charged.

The operating instructions for cutting stainless steel are approximately the same as for cutting mild steel, and the speed of the cut is the same as for cuts of comparable quality. The flux consumption for cutting thicknesses of 1 to 5 inches averages about 1 ounce per minute of operation. Only normal preheat-the same as required for standard cutting operations-is needed. The process is recommended for quality cuts up to 3 inches in thickness, and rough cuts in greater thicknesses up to 6 inches.

Fig. 1 shows a cut started in a stainless-steel plate 2 1/2 inches thick, the length of the cut being 10 1/2 inches. This cut is made in 18-8 stainless steel in three minutes.

The Comparoscope-An Optical Instrument

for Evaluating Surface Finishes

N instrument for comparing the finish of a stand

ard or with another work-piece has been developed by William F. Klemm of the ComparInstrument Co., 16179 Hamilton Ave., Detroit 3, Mich. This instrument differs to a considerable extent in the principles upon which it is based from the surface finish measuring instruments so far available. It compares surface finishes by optical means, is simple in operation, and gives answers to questions relating to surface finish instantaneously.

The basic principle underlying the Comparoscope is the fact that a light beam thrown at a given angle upon a perfect surface, such as a mirror, will be reflected from this surface at the same angle. If an observer is viewing such a perfect surface in a direction normal to the surface and all reflected light reaching his eye at an angle is shielded from it, no light will reach his eye and the surface will appear black. If the surface has a number of interruptions, such as caused by the various finishing methods, these interruptions will form minute prismatic surfaces, throwing light beams back into the observer's eye. Therefore, the more numerous and wider these surface interruptions are, the brighter such a surface will appear to the eye of the observer who inspects it through the Comparoscope. It is now generally considered that the depth of surface interruptions has little bearing on the actual wear of surfaces.

The instrument is principally a dual microscope, in which an accepted standard or master is clamped in the master section of the instrument. This master may have been determined as having a desirable finish by various methods, or by actual wear tests. The instrument is placed upon the surface to be examined and the built-in illumination of the instrument is turned on. In the eye-piece appear the image of the master and that of the piece being tested. Since the same source of illumination (a condensed filament, 6-volt lamp) is used at an equal distance from both surfaces, the illumination of both images is identical. Photographs taken through the instrument show differences between two surfaces of as little as 1 R.M.S., when checked by equipment that records finishes in R.M.S. units.

The Comparoscope in Use for Inspecting
a Finished Surface

in the direction of the intended motion of such parts, the image will give a direct indication of the reaction of such a surface to its mating member. The instrument shows that it is obviously wrong to finish reciprocating parts, such as pistons, in the same direction as rotating parts, such as driving shafts. When parts have been "superfinished," they show the same surface value, regardless of the direction in which the instrument may be placed on the surface. This type of finish will wear equally well, no matter what the direction of motion.

One important feature claimed for the Comparoscope is that it places emphasis on, and proves the importance of, the direction of finish in relation to the direction of motion of a part subjected to wear. By placing the instrument

By sliding the knob on the side of the instrument, the image of the master can be eliminated.

The instrument can then be used as a self-illuminated shop microscope.

The Comparoscope also offers a means for comparing two apparently similar types of fabrics or textiles. Granular material, as well as paint and pigments in powder form, can also be examined and compared.

The importance of surface finish has been more and more recognized during recent years, and with this recognition have come improved instruments for its evaluation.

Editorial Comment

Now that the war in the East, like the war in Europe, has come to a sudden end, credit for the victory will go mainly in two directions. First and foremost we must give credit to our fighting men on land, on sea, and in the air. The officers and men who planned and carried out

all the enterprises that culminated in final vic

tory have displayed marvelous ability and courage.

The victory could never have been won except for what these men have done.

However, no armies or navies, no matter how able and courageous their personnel, can achieve results unless they are supplied with the weap

We Should Not Forget the Contribution of Industry to Victory

ons of war at the right time and in sufficient quantities. Hence, credit for the victory must also go to our industriesthe industries that, as has so often been pointed out in MACHINERY, in an incredibly short time converted from the production of civilian necessities to the making of the "tools of war."

accomplished in war production. A group of men without whom these results could not have been achieved consists of the thousands of engineers who planned the methods of production and designed the means by which all the imple

Stupendous Job of
Tool Engineers and
Production Men

ments of warfare were so quickly and efficiently produced, the ships built, and the planes constructed. In performing their enormous task, they undertook no routine job. Most of the problems solved were new to them, but the results testify to the fact that their experience and ingenuity were equal to the job. Though confronted with applications wholly foreign to them, in a few months they made the wheels in the converted plants turn again, producing long-range guns, aircraft engines, tanks, shells, and fuses in place of all the civilian products they had formerly furnished to a peaceful nation. Many of these engineers, in the earlier days of the war especially, literally worked day and night to complete their tasks in the shortest possible time.

Nor should the millions of workers be overlooked who performed their tasks from day to day without faltering. Especially should credit be given to those skilled workers who faithfully performed their allotted tasks with the full realization of the seriousness of the dangers

To the men of industry-all the way from the leaders and managers to the men operating machines and performing assembly operations— should go the credit they so amply deserve. First, there are the industrial leaders who conceived the possibility of performing unheard-of feats of manufacturing and who entered upon this work with wholehearted enthusiasm. In many cases, they threw overboard all considerations of the consequences to their business and to themselves after the war. They built and equipped factories that they will be able to keep fully Stayed on the busy only with difficulty in peacetime years. They staked the future of their enterprises on one object-victory.

Next, we must not forget the contribution made by the machine tool builders of the country who produced the necessary war production machines by expanding their output sevenfold, compared with their greatest peacetime production. From an annual peak output valued at about $200,000,000, this industry, within a short space of time, so developed its facilities that it was producing at the rate of approximately $1,500,000,000 a year.

But it is not the leaders and managers of industry alone who deserve credit for what was

Workers who Faith

Job Did Their Part

facing the nationthe men who worked long hours to provide the fighting forces with the equipment needed and who refused to listen to that group of self-appointed leaders of labor who fomented strife and strikes at a time when tens of thousands of our young men were giving their lives for the nation.

Over two years ago, MACHINERY commented: "When the war is over, let us not forget to add to the credit that we shall then give to the leaders of our armed forces and to the fighting men, the credit that is due our industrial leaders and their supervisory staff, our engineers, and the conscientious workers throughout industry." Now that the war is over, it is due these men that their services be again emphasized.

Ingenious Mechanical Movements

Mechanisms Selected by Experienced Machine Designers
as Typical Examples Applicable in the Construction of
Automatic Machines and Other Devices