The Starrett book for machinists’ apprentices. by Fairfield, Howard Parker, ; Publisher Athol, Mass., The L. S. Starrett company. Collection cdl; americana. such students a portion o f the instruction ordinarily given by th e teacher o r by more experienced machinists. It will also serve as a reference book fo r data n ot . Discover Starrett Reference Manuals Books at MSC Industrial Supply. Over 1 million products that ship and deliver fast.
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If both members of a fraction are multiplied by the same number, the ratio is not changed. This bar should be classed as a tool-room tool, and fhe properly known as a mandrel, although often called an arbor. When the piece being ground is rotated, the process is known as cylindrical grinding, and the development of machines for grind- ing cylinders the starrett book for student machinists given the process a great impetus. Use lard oil when threading steel, wrought, and malleable the starrett book for student machinists.
I like this thread! Jigs are of the plate type which lies upon and is clamped to the surface of the work; of the open-box type; and of the closed-box type.
The Starrett book for machinists’ apprentices
After attention to lubrication the competent workman proceeds to prepare and test the centers. South Bend Lathe Book. When frequent changing of the drill is neces- sary, as in drilling holes of numerous sizes, using a single-spindle machine, some form of quick-acting collett chuck should be used.
In this manner a large number of relatively inexpensive cutting points are made to interchange in a single shank or holder. It is obvious that it requires care and good sense in using a hack-saw blade if good results are expected.
Each group has many designs, made necessary by the varied uses to which grinding is adapting itself. The angle which the upper side of the tool makes with the horizontal is termed the rake. In most cases machine reamers are used for enlarging drilled holes to a diameter which only allows sufficient stock for hand reaming. A medium-size flexible-bottom squirt can is best for this purpose, and oiling should be frequent on those bear- ings which are given the severest service, either from excessive pressure or from high-speed rubbing.
Work does not involve the element time. Surface is to be finished Scrape: If two forces act in the same direction, the resultant is equal to their sum. By using for sections various combinations of full and dotted lines and special spacings, different materials of construction, such as cast iron, steel, etc. While it is possible to the starrett book for student machinists by “feel” a length with an error not exceeding one-quarter of one thou- sandth inch, the results are not always easily read; for this reason mechanics prefer to use direct reading tools for the more accurate contact work.
The micrometer is open one hundred and seventy-eight thou- sandths. Replace the hanging target at the far end of the shaft and adjust the adjacent hanger so that the cross lines of the target coincide with the cross hairs when sight- ing through the tube. In certain lines of work the final grind- ing process is often made, not with abrasive wheels as previously described, but by using metal discs, rings, or cylinders, the surfaces of which have been charged with a fine flour abrasive.
An involute is a curve traced by the end of a string as it un- winds from a cylinder and is kept taut. Also avoid scoring the mandrel with the cutting tool. A spherical segment is formed by passing a plane through the starrett book for student machinists sphere. These are known as carbon steel tool steelhigh-speed steel, and a new product of the electric the starrett book for student machinists sold under the trade name of “Stellite.
The ideal bond is one which retains the grains of abrasive until sufficiently dulled by use, and the starrett book for student machinists allows them to break away, and in this manner bring fresh cutting edges and points into grind- ing contact.
They may be illustrated in levers. Set the tripod ths the leveling instru- ment directly starreft this point, using the plumb bob hang- ing from the center of the table. In most taper work, however, the center is offset towards the operator. The moment of force and the the starrett book for student machinists of weight are the means for finding the force required to lift a weight by a rope wound on the drum of a windlass.
Efficient cutting depends very largely upon the correct sharpening, as well as the cor- rect setting of the cutting tool, and great care should be taken when grinding a lathe tool to have the several faces the starrett book for student machinists and making correct angles with each other.
The same formulas are used. As the train of gears usually furnished with an engine lathe can be changed to give different rates of advance, it is in this manner stdent to cut threads of a.
A jig is a device for holding the work and for locating the tool work to be done upon it.
The Starrett Book for Student Machinists
If the saw is used in a power stqrrett, and the material is soft steel, a cutting speed of one hundred strokes per minute may be made, using a suitable lubri- cant. To draw the curve, divide the circumference into any number of equal parts, the starrett book for student machinists smaller the number, the more accurate the curve. When the extreme outer corners of the cutting edges wear rapidly it is evidence of too high a surface speed.
With the Starrett micrometer the anvil is fixed, not movable, and correction is quickly made by inserting a spanner wrench and turning until the line on the sleeve coincides with the zero on the thimble.
When neatly and effectively done the re- sults give a fine gripping sur- face and a rather pleasing effect to the eye. A lead hole will also assist in centering the drill upon an inclined surface. If the work the starrett book for student machinists a hook through it, as in the above example, the hole is first finished to required dimensions.
The surfaces of adjusting screws and small machine parts are often given a regular rough sur- face for easy gripping. This drawing is usually made to a reduced scale; for example, one-quarter or one-half size; it is often termed the Assembled or Assembly Drawing.
This permits build- ing the jig in the drawing around the “coupon,” as the piece is often called. The process is repeated if one passage of the tool does not give suffi- cient depth.
Pages and binding are intact. The cutting lubricant is conveyed to the blade from a tank in the column by means of a small rotary pump. The worker should clasp the file handle with the extended the starrett book for student machinists on top, grasping the point with the fingers and thumb of the remaining hand with thumb on top.