S. W. Goodyear
As a constant reader of your valuable paper I come in contact monthly with opinions and formulas and advertisements of books and recipes for hardening and tempering steel, and still the inquiries continue to come for best methods. "How shall I harden and temper granite drills?" says one, and at once come answers which advise use of rain water, brine, boiled linseed oil and salt. " A drop of water will prove to be ruinous." Now there must be in this, as in all other mechanical processes, a foundation fact. Good work in hardening is done by the use of rain water, well water, spring water, water saturated with salt and water in which have been a thousand and one nostrums, and oil is used in the same way, clear in great variety beside linseed, with additions of a variety of other things, all with good results sometimes, and with occasional " bad luck " as steel varies from what it should be or, begging the pardon of the hardener, the treatment is not just right.
If of two diametrically opposite methods of heating and cooling it can be said that both bring first-class results, one equally as good as the other, notwithstanding the advocate of each method persists in standing up for his own and denouncing the other as worthless and ruinous, is it not fair to suppose that the real foundation on which successful hardening depends lies deeper than any particular formula? A se. cret ? No, a fact, free as sunlight, and that fact is that hardening depends upon heat and sudden cooling-Rock drills - granite drills - let us make a good one-Don't forge it to shape at a low red heat, as someone advises. Get a good mellow heat and be sure the heat is even, clear through, not a heat got too quickly and only at the surface. Do not continue mauling and hammering down to a black heat, but stop with heat remaining sufficient so that if the steel used is of a right temper for first-class rock drills it will harden like glass at heat at which hammering ceases, at the thin edge.
In fact, I once watched for an hour a hand mining drill dresser who sharpened worn drills as they came to him from the mine, entirely with the hammer and a brush of the file, and hardened and tempered them, for there was no second operation of tempering, by dropping them into a bath of salt water, right from the anvil and hammer, without reheating, and by my test with a file every one was hard, and by testimony of users of the drills no better drills had ever been used by them. I saw no broken drills.
"Then," says somebody, " you advise this?" I say, "No ; but it is one way, and there are as many apparently different ways as there are different steels," and just here comes up one of the most important factors in the whole matter - i. e., right steel for any particular use. The man who says, " Follow my formula for heating, and use my bath for quenching, and no matter what the steel is, you will succeed," has certainly another guess coming, for if he has been so fortunate as to always happen to use a steel for which a good, bright orange color is safe, he will some day strike one which, with the same heat treatment will go to pieces like so much glass, and the chances are that it will be the very steel he should have used all along.
I said " fortunate," did I not? Ye&, and in that very way are thousands of steel users measuring suc-cess-i. e., "the steel which will bear most abuse, highest heat for hardening and still not break, but do good work," is held up as a standard, while there are some who measure success by comparatively ultimate value of hardened pieces, as quoting one satisfied steel user who was sounding the praises of a steel new to him, when asked to give some definite statement of comparative superiority over the old standard imported steel he had sworn by and thought he could not live without.
" Three weeks against three days." Another who, after years of practice with best average production from certain dies being fifty thousand, tries a new steel and says, " five hundred thousand." " High speed steel?" "No, but steel which can be annealed and tempered by old-fashioned methods. High speed steel has its uses, and is doing marvellous work, such wonderful work as to make us doubt the veracity of some who keep tabs and publish records of speeds, feed, depth of cut and aggregate removal of stock in given time, lifetime of tools, etc., and still investigation will show them to be in the main true.
I will wind up by stating that, as I see it, the subject of treatment of steel is inexhaustible. Best in steel is none too good; so with treatment; and to be fitted up with all the best appliances for proper hardening is desirable, and in no other way is it likely that money is expended more judiciously, and still I have before me the two-days-old vision, not of a stolid, self-reliant, self-possessed hardener, pumping wind by hand on an old-fashioned portable forge, one of the pump-handle variety, with a hatful of fuel, and it not charcoal, but coked bituminous coal, to heat as bad a tool to harden as often comes to the lot of any man; little fire, little wind, but constant care, measuring the stroke of the lever as carefully as though a life depended, and it did, i. e., the life of the costly tool. "She's coming, coming good," says the man at the lever as he peeps through the thin layer of coals over the intricate shaped face of the tool being heated. It is a forming tool some 3 in. wide by 1 in. thick by 5 or 6 in. long, intent being to harden some 2 or 2 1/2 in. in length of the working end, and " she does come," first a perceptible red and gradually changing color to that beautiful shade which delights the successful hardener.
"Coming good," says the man. Said I, "Yes, and it is about there," and out it comes and into clear water and is kept there, not until cold but until hardening has taken place and then the old hardener violently works the pump handle some more, making the sparks fly, and held the tool over the fire to equalize the heat, and with the tool as hard as glass, and a heat just inside of the tempering to straw color, the job is done. Methods most primitive possible, and still this man had it under his hat to do a good job, no matter what the facilities were; from start to finish he had been as alert as would have been the most experienced trout fisherman with a big one hooked and playing to land him. Such men are prizes.-"Blacksmith and Wheelwright."