Tips and tricks
Dies and die making
DIES AND DIE MAKING
BY J. L. LUCAS, 1897
DOWNLOAD FREE BOOK:
Dies and die making
PREFACE
In putting this work before the public, the author is well aware that it will meet with criticism from those who are better informed on the subject than he; but a careful search in the bookstores and through the catalogues of the largest publishing firms failing to show a work of this kind, has led him to take up the task; and, although better fitted by experience for the file than the pen, lias done the best that he could. It is essentially a shop book, written by a shopman, and intended for shop use.
Many of the dies shown were made by him personally, others were made from sketches, and under his personal supervision, while others were made and used in various pressrooms of which he had an intimate knowledge; and the rest, especially those on bicycle tools, are from the columns of the American Machinist and other papers devoted to mechanics.
Certain parts of these articles have been published in the columns of the American Machinist; also a few pages can be found in the catalogue of the Mossberg & Granville Manuf g Co., which were contributed by the writer.
Many of the dies shown were made by him personally, others were made from sketches, and under his personal supervision, while others were made and used in various pressrooms of which he had an intimate knowledge; and the rest, especially those on bicycle tools, are from the columns of the American Machinist and other papers devoted to mechanics.
Certain parts of these articles have been published in the columns of the American Machinist; also a few pages can be found in the catalogue of the Mossberg & Granville Manuf g Co., which were contributed by the writer.
THE ORIGIN OF DIES
The origin of dies is, without doubt, very obscure. Perhaps the frontispiece in Mr. Oberlin Smith's excellent work on "The Press Working of Metals " will give as good a likeness of the original die-maker as we shall ever find. A search in some of the best libraries and museums has failed to reveal any information that is at all ancient, and that can be relied upon. The samples of old coins that have been handed down to us, show that the art of die-sinking was known to the ancient Greeks at least eight hundred years before the Christian era, but they do not show that the use of punches and dies was equally well known.
The first record of punches and dies used in a machine or press (having guides or ways to ensure the punch entering the die correctly) is in the fifteenth century, when they were used in the manufacture of hinges, by a German locksmith. Later on, in the sixteenth century, we find them in use both in Germany and France; and as early as the year 1796 a patent was granted to one u De Vere," of France, for dies for punching and drawing of sheet metal.
In 1827, M. Gagalott took out a patent for press and tools for drawing up cartridge shells from sheet copper. These were nearly the same shape as those in use at the present time, and the dies were probably of the same design.
In the article on "Drawing Presses," on page 22, will be found a history of the first drawing press made in this country, used for drawing up kitchen utensils, - the facts of which can lie vouched for, and were related to the writer by one of the workmen employed, Mr. J. L. Kirby, now superintendent of the Dover Stamping Co. The facts relating to the use of drop presses for "striking up" sheet metal were also obtained from this same source.
The author would be pleased to learn any facts relating to the use of dies prior to that time, and would like to hear from any of his readers on this subject.
PROPER SELECTION OF STEEL FOR DIES
Steel intended for punches and dies should in all cases when possible be ordered directly from the mill, giving all the information possible as to the use to which it is to be put, and the class of work it is intended to punch. The steel should be annealed at the mill, as the extra cost is more than offset by the ease which it is worked, and the certainty with which it can be hardened.
Much of the trouble now experienced with die steel could be avoided by this method, except that caused by improper heating by the smith in hardening. Steel for dies should be free from seams and flaws and of even color, not to be high in carbon (from .007 to .009 per cent, is a good proportion) and capable of being hardened without shrinking or changing its shape to any great extent, except in the case of drawing dies, where this fault is a desirable one, as the die can be (when worn) reduced to size by being re-hardened, thus increasing the amount of work the die will perform.
When you have once found a grade of steel that you know to be suited to your work, k 'stick to it" (and don't be induced by a smart agent with a box of cigars to give him an order even if he claims that he has a brand that will not shrink or change in the least, and would stand any degree of heat without injury). If you find that it is impossible to get any one grade that will till the bill for all kinds of dies, mark each brand so that you or your men can tell at a glance what kind of stock it is. A good way is to paint a stripe the whole length of the bar, and a different color for each make or brand of stock. The stripe the whole length of the bar, indicates the make no matter how short the piece may be, and as shellac is usually the most abundant paint in the shop, use red, black, and white shellac, and but three grades of steel.
For drop-press work for cold dropping, use a steel that is a little high in carbon, and give the dies plenty of stock to avoid breakage. For very large dies for drop-press work and where they are to be used on thin stock, as tin or sheet iron, a die made of a steel easting and case hardened will give good results. Where a large amount of labor is necessary to produce the die as in the case of watch or clock dies, get the best steel that can be found, as it is a poor policy to try and use a poor grade of steel for intricate work.
MAKING A PLAIN PUNCH AND DIE
Having found a brand of steel that is suitable for the work to be punched it should first be machined to the proper size and shape, which will depend on the class of work it is to do, and the style of die-shoe it is intended to he used in. A good way, and one that is adapted to a large class of work, is to bevel the edge of the bar to an angle of 10 degrees, leaving the ends as they come from the forge or saw. To get out these blanks cheaply, cut the steel up into two or three lengths, plane up and bevel the edges to the proper angle, and then saw off as wanted to the required lengths.
This style of die can he held by a key or set screws, whichever the practice may he. The upper surface of the die should he finished on the surface grinder if there is one, or by hand with the use of the file and scraper, as the time thus spent is saved in the laying out of the die and the work can he laid out better, and more distinctly than on the rough machined surface of the blank.
The surface of the die is now covered with what the die-maker calls “ blueing,” hut what is really sulphate of copper, and is made by dissolving sulphate of copper or blue vitriol in water (a proportion of ten parts of water and one of crystals makes a good solution), this leaves a thin deposit of copper on the surface of the steel, leaving an excellent surface for laving out the die. The outline of the piece to he punched should now be traced on the upper surface of the die: care should he taken in laying out to avoid waste of metal, also that the grain of the stock to he punched runs in the proper direction so that it can he easily prepared for punching.
The die being neatly laid out from either drawing or template, all round corners should be drilled with a drill of the proper diameter to leave the corner the shape, and then reamed with a reamer of the proper taper to give the die the clearance wanted; the rest of the stock is now removed by drilling. Every die-maker has a way of his own for this part of the work; one will drill so that the holes will cut into each other and thus avoid broaching, while the next man will drill holes.
If the die is for a press room using a large number of dies, it should be marked with a shelf and rack number, so that it can be quickly found by the die-setter; the die is now ready to harden.
The die being finished, the blank for the punch, which, if the shape of the die demands it should be a forged one (hut if possible, should be cut from the annealed bar), should be machined on both ends, and one end finished, then clamped firmly on to the face of the die, using a die clamp (Fig. 3); now scribe through the die, and mark the outline of the punch on the finished end of the blank. This should be nicely marked with a centre punch. The stock can best be removed by the use of a milling machine, as a base or shoulder, of the same shape but of a larger area, can be more easily left with this tool than the shaper. The object of this base is to give the punch better support, and increase the length of time it can be used.
BLANKING DIES
A set of blanking dies consist of a male die, or punch, and the lower or female die; they are made in almost every form and size for cutting out flat blanks from steel, iron, paper, mica, etc. Usually both punch and die are hardened and tempered; sometimes the punch is left soft, and as it gets worn, is set out and refitted by being forced or shoved into the die ; sometimes it is best to reverse this operation, as in punching paper, playing cards, etc., and harden the punch and leave the die soft.
A shear is usually given to the punch or die, determined by the work it has to do; when it is intended to use the blanks, or pieces punched out, the shear should be given to the die, as less distortion is given to the metal by this method, but where the hole is the object sought, - as in rivet holes in boiler plates, etc., - the shear should be given to the punch.
Cutting or blanking dies are usually held in a shoe or die holder, or if a large die, it is fastened to the bed of the press direct, but as a rule the fewer pieces intervening between the press and the die the better results will be obtained.
Very large blanking dies are usually made in one of two ways; either as rings set in a cast-iron holder, or by welding the rings directly on to a wrought-iron holder or die plate; the latter method is the best in making plain dies, but cannot be used in compound dies. The welding of the steel rings together, and then on to the wrought-iron plate, calls for good work on the part of the smith. Some of the finest work of this kind we have ever seen is done at the works of the E. W. Bliss Co., at Brooklyn, N. Y., large steel rings, both round and square, being welded to wrought-iron beds or die-plates, and the joints so perfect they could scarcely be detected.
In the former method the rings are first welded and then turned, hardened, and ground true in the universal grinder, then set in a groove turned in the holder as shown in the sketch (Fig. 9, page 20), and held there by being bolted from the back of the holder. The distortion of these rings, caused by long use of the die, is something that is hard to account for, the lower or die ring often being dished to such an extent as to close in the top or cutting edge of the die so much that it is necessary to grind it out and refit it to the punch, a ring of 20" diameter, and made of 2" square steel, being out over |" on the bottom or lower edge; this is caused, it is thought, by the strain left in the ring in hardening, and which is released by the grinding of the die.
The power required to blank out a piece of metal depends largely on the shape of the blank and the number of cutting inches in the die; a long, narrow blank requiring more power than a round blank of the same area, the shear of the dies being equal. If the work will admit of the face of the punch 1 icing slightly rounding, less pressure will be required than with a flat-ended punch.
The first thing to be considered to determine whether a punch and die should be used to produce work, is the number of pieces wanted. If it is standard work, and the demand is 100 or more per week, it is both desirable and economical to have a die made, for after the die is once made the work can be produced at a very low cost. Oftentimes when a large number of pieces are wanted, and a power feed is used, the cost will not exceed two cents per 1,000 blanks.
DOWNLOAD FREE BOOK: Dies and die making
The first record of punches and dies used in a machine or press (having guides or ways to ensure the punch entering the die correctly) is in the fifteenth century, when they were used in the manufacture of hinges, by a German locksmith. Later on, in the sixteenth century, we find them in use both in Germany and France; and as early as the year 1796 a patent was granted to one u De Vere," of France, for dies for punching and drawing of sheet metal.
In 1827, M. Gagalott took out a patent for press and tools for drawing up cartridge shells from sheet copper. These were nearly the same shape as those in use at the present time, and the dies were probably of the same design.
In the article on "Drawing Presses," on page 22, will be found a history of the first drawing press made in this country, used for drawing up kitchen utensils, - the facts of which can lie vouched for, and were related to the writer by one of the workmen employed, Mr. J. L. Kirby, now superintendent of the Dover Stamping Co. The facts relating to the use of drop presses for "striking up" sheet metal were also obtained from this same source.
The author would be pleased to learn any facts relating to the use of dies prior to that time, and would like to hear from any of his readers on this subject.
PROPER SELECTION OF STEEL FOR DIES
Steel intended for punches and dies should in all cases when possible be ordered directly from the mill, giving all the information possible as to the use to which it is to be put, and the class of work it is intended to punch. The steel should be annealed at the mill, as the extra cost is more than offset by the ease which it is worked, and the certainty with which it can be hardened.
Much of the trouble now experienced with die steel could be avoided by this method, except that caused by improper heating by the smith in hardening. Steel for dies should be free from seams and flaws and of even color, not to be high in carbon (from .007 to .009 per cent, is a good proportion) and capable of being hardened without shrinking or changing its shape to any great extent, except in the case of drawing dies, where this fault is a desirable one, as the die can be (when worn) reduced to size by being re-hardened, thus increasing the amount of work the die will perform.
When you have once found a grade of steel that you know to be suited to your work, k 'stick to it" (and don't be induced by a smart agent with a box of cigars to give him an order even if he claims that he has a brand that will not shrink or change in the least, and would stand any degree of heat without injury). If you find that it is impossible to get any one grade that will till the bill for all kinds of dies, mark each brand so that you or your men can tell at a glance what kind of stock it is. A good way is to paint a stripe the whole length of the bar, and a different color for each make or brand of stock. The stripe the whole length of the bar, indicates the make no matter how short the piece may be, and as shellac is usually the most abundant paint in the shop, use red, black, and white shellac, and but three grades of steel.
For drop-press work for cold dropping, use a steel that is a little high in carbon, and give the dies plenty of stock to avoid breakage. For very large dies for drop-press work and where they are to be used on thin stock, as tin or sheet iron, a die made of a steel easting and case hardened will give good results. Where a large amount of labor is necessary to produce the die as in the case of watch or clock dies, get the best steel that can be found, as it is a poor policy to try and use a poor grade of steel for intricate work.
MAKING A PLAIN PUNCH AND DIE
Having found a brand of steel that is suitable for the work to be punched it should first be machined to the proper size and shape, which will depend on the class of work it is to do, and the style of die-shoe it is intended to he used in. A good way, and one that is adapted to a large class of work, is to bevel the edge of the bar to an angle of 10 degrees, leaving the ends as they come from the forge or saw. To get out these blanks cheaply, cut the steel up into two or three lengths, plane up and bevel the edges to the proper angle, and then saw off as wanted to the required lengths.
This style of die can he held by a key or set screws, whichever the practice may he. The upper surface of the die should he finished on the surface grinder if there is one, or by hand with the use of the file and scraper, as the time thus spent is saved in the laying out of the die and the work can he laid out better, and more distinctly than on the rough machined surface of the blank.
The surface of the die is now covered with what the die-maker calls “ blueing,” hut what is really sulphate of copper, and is made by dissolving sulphate of copper or blue vitriol in water (a proportion of ten parts of water and one of crystals makes a good solution), this leaves a thin deposit of copper on the surface of the steel, leaving an excellent surface for laving out the die. The outline of the piece to he punched should now be traced on the upper surface of the die: care should he taken in laying out to avoid waste of metal, also that the grain of the stock to he punched runs in the proper direction so that it can he easily prepared for punching.
The die being neatly laid out from either drawing or template, all round corners should be drilled with a drill of the proper diameter to leave the corner the shape, and then reamed with a reamer of the proper taper to give the die the clearance wanted; the rest of the stock is now removed by drilling. Every die-maker has a way of his own for this part of the work; one will drill so that the holes will cut into each other and thus avoid broaching, while the next man will drill holes.
If the die is for a press room using a large number of dies, it should be marked with a shelf and rack number, so that it can be quickly found by the die-setter; the die is now ready to harden.
The die being finished, the blank for the punch, which, if the shape of the die demands it should be a forged one (hut if possible, should be cut from the annealed bar), should be machined on both ends, and one end finished, then clamped firmly on to the face of the die, using a die clamp (Fig. 3); now scribe through the die, and mark the outline of the punch on the finished end of the blank. This should be nicely marked with a centre punch. The stock can best be removed by the use of a milling machine, as a base or shoulder, of the same shape but of a larger area, can be more easily left with this tool than the shaper. The object of this base is to give the punch better support, and increase the length of time it can be used.
BLANKING DIES
A set of blanking dies consist of a male die, or punch, and the lower or female die; they are made in almost every form and size for cutting out flat blanks from steel, iron, paper, mica, etc. Usually both punch and die are hardened and tempered; sometimes the punch is left soft, and as it gets worn, is set out and refitted by being forced or shoved into the die ; sometimes it is best to reverse this operation, as in punching paper, playing cards, etc., and harden the punch and leave the die soft.
A shear is usually given to the punch or die, determined by the work it has to do; when it is intended to use the blanks, or pieces punched out, the shear should be given to the die, as less distortion is given to the metal by this method, but where the hole is the object sought, - as in rivet holes in boiler plates, etc., - the shear should be given to the punch.
Cutting or blanking dies are usually held in a shoe or die holder, or if a large die, it is fastened to the bed of the press direct, but as a rule the fewer pieces intervening between the press and the die the better results will be obtained.
Very large blanking dies are usually made in one of two ways; either as rings set in a cast-iron holder, or by welding the rings directly on to a wrought-iron holder or die plate; the latter method is the best in making plain dies, but cannot be used in compound dies. The welding of the steel rings together, and then on to the wrought-iron plate, calls for good work on the part of the smith. Some of the finest work of this kind we have ever seen is done at the works of the E. W. Bliss Co., at Brooklyn, N. Y., large steel rings, both round and square, being welded to wrought-iron beds or die-plates, and the joints so perfect they could scarcely be detected.
In the former method the rings are first welded and then turned, hardened, and ground true in the universal grinder, then set in a groove turned in the holder as shown in the sketch (Fig. 9, page 20), and held there by being bolted from the back of the holder. The distortion of these rings, caused by long use of the die, is something that is hard to account for, the lower or die ring often being dished to such an extent as to close in the top or cutting edge of the die so much that it is necessary to grind it out and refit it to the punch, a ring of 20" diameter, and made of 2" square steel, being out over |" on the bottom or lower edge; this is caused, it is thought, by the strain left in the ring in hardening, and which is released by the grinding of the die.
The power required to blank out a piece of metal depends largely on the shape of the blank and the number of cutting inches in the die; a long, narrow blank requiring more power than a round blank of the same area, the shear of the dies being equal. If the work will admit of the face of the punch 1 icing slightly rounding, less pressure will be required than with a flat-ended punch.
The first thing to be considered to determine whether a punch and die should be used to produce work, is the number of pieces wanted. If it is standard work, and the demand is 100 or more per week, it is both desirable and economical to have a die made, for after the die is once made the work can be produced at a very low cost. Oftentimes when a large number of pieces are wanted, and a power feed is used, the cost will not exceed two cents per 1,000 blanks.
DOWNLOAD FREE BOOK: Dies and die making
Free books category: