Making and Hardening Tools (Part One)

Twist Drills

“Search others for their virtues, thyself for thy faults.”

To make a twist drill for drilling iron, prepare the shank first, the part to be fitted in the drill chuck.  Next flatten the steel, and make it fully as wide as the size you wish to have the drill when finished.  Now heat the flattened part the whole length, place the shank in the vise, and with a pair of tongs take hold of the extreme end of the drill, and give one turn to the left; that is, the twist should be just once turned around for the whole length of the drill.  Of course, it is difficult to make such a drill by hand, and get a uniform thickness the whole way.  In order to make a perfect drill, the material should be turned, which is essential when deep holes are to be drilled.  For shallow drilling, a home-made drill will do, but for intricate and complicated work, use a Cleveland Twist Drill Co. drill.  When the drill is ready for hardening, heat to a low red heat the whole length of the twist, cool off in water, then polish, and place over a hot bar of iron, and draw the temper to a copper color.

Drills for Chilled Iron

Drills for chilled iron or tempered steel must be made a trifle heavier, with the share a little convexed.  They should be hardened in soft water at a low heat.  Draw no temper.  Dip the drill in water only deep enough to cover the cutting part.  In drilling, have an even pressure on the drill, and use water, not oil, to keep the drill cool.

Mill Picks

When the pick is dressed, heat to the proper hardening heat, cool off in salt water, dip the pick about half an inch in the water only, and cool off.  Draw no temper.  If the heat is right, and the pick has not been overheated during dressing, the smith will soon be able to do this kind of work first rate, provided, however, that the steel is a high percentage carbon steel.

Axes

In our time, axes are cheap, and blacksmiths so ignorant in regard to making and dressing of same, that some people never think of going to the smith with a broken or worn axe, for they well know that in most cases it is money thrown away.  In dressing axes, the greater danger lies in overheating, because the extreme edge, being thin, is liable to become overheated before the heavier part of the axe is hot enough to dress; and it matters not how the axe is hardened and tempered, if the steel is once overheated, there is nothing to do but either to cut the burnt parts off or throw the axe in the scrap pile.  When hammering the axe out, hammer equally from both sides, or the axe will be flat on one side and convexed on the other.  If one corner is longer than the other, trim it off.  When ready to harden, heat an even low red heat, cool off about two inches in water not too cold, then polish or brighten, and watch the temper.  It will be noticed that the temper very seldom comes back even; therefore have a wet rag or a piece of ice, and touch the place where the temper runs out too quickly.  By this method an axe can get an even temper, which is not possible when the axe Is hardened in oil, and the oil burnt off, for the smith will then know nothing of the uneven return of the temper,  When the color turns to blue, cool off.

Granite Tools

Granite tools are hardened by the same method given for “Mill Picks.”

Well Drills

For well drills, – which are the same as rock drills, the only difference being the size, – the same method should be pursued as in rock drills.  The temper might be a little softer; and in dressing, care should be taken to have all he corners diagonally of the same size.

Hardening Files, Taps and Dies

Fill a cast-iron bucket with lead; set over the fire until the lead is red hot, – in other words, has the heat the file or tap should have when hardened; then place the file in the bucket, tanged end up.  Have the bucket covered to the middle, and place the file with the tanged end against the covering, and the file will float in the lead, and hold itself against the cover, for steel is lighter than lead.  This will also prevent the tong from getting hot, as that would break it if it was of the same heat as the file.  By this method of heating, a uniform heat will be obtained, which is essential in all kinds of hardening, and especially in files; for the files are liable to warp even at uniform heat, and much more so if the heat is uneven.  When the file is of the proper heat, place in the hardening fluid end first, and draw out edgewise, to prevent warping, which is the result of moving the file in the water while there is yet heat in it to sizzle when take out.  Now, if it is crooked, place it between two pins fastened in the side of the tank, with the concaved side up.  Now take some water in one hand, and sprinkle over the curve of the file, while you hold it with the other hand between the pins in a straight position.  When cool, it will be straight.  I have noticed that a file hardener will become very adept after some practice, and it is very seldom a file is found to be crooked.  Taps and dies are heated the same way, and cooled off entirely, then brightened, and held over a gas burner, the flame forced onto them with a blow pipe until they show a yellow straw color; then cool off in water.

Stone Hammers

Dressing and hardening stone hammers is some of the simplest work to be done by a smith; and, still, if one inquires of a stone mason how many smiths he knows who can do a good job, you will find that he will mention probably one smith whom he knows, who is doing this work right.  A smith who has learned the elementary rules in handling tool steel cannot fail to do a good job every time.  The only precaution to take is to watch for the heat so as not to overheat; for the edges or corners of the hammer, if it is a large sized one, are liable to burn before the steel is hot enough in the center of the hammer to work.  Heat to a red heat, and make the corners full, with a concaved face; this cavity to run along the length of the face.  When dressed, heat to a high red heat, dip in ice cold water from one to two inches, and keep the hammer moving in the water so as to cool it off quick.  Draw no temper, but cool off.  When one end is done, place a wet rag on that end while you heat the other for hardening.  Both ends should be dressed before either end is heated for hardening.  If one end is sharp, that end must be handled with a little more care.  In this end, draw the temper until it shows a straw color.  A stone hammer, rock or stone tools should not be case hardened; for if a compound of any kind is used, it will only serve to produce a hard shell, which will scale off.  Use nothing but water.  A weak solution of common salt may be used.