A Forge

For Hand Punchcutting in Steel

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Therefore, indeed, a Letter-Cutter should have a forge set up - Moxon. (1683).

1. Introduction

A small blacksmith's forge (meaning the forge itself, an anvil, and associated tools) has several uses in traditional punchcutting. If the punchcutter makes his or her own punch blanks, it may be used for shaping and cutting them. It may be used for annealing punch steel. It may also be used for hardening and tempering punches.

The forge used by the punchcutter does not differ from the ordinary blacksmith's forge, anvil, etc., save only that it may be relatively small.

With modern tool steels readily available in convenient stock sizes, it is no longer necessary to forge punch blanks, and alternative heat treating methods are available. So unless the contemporary punchcutter wishes to follow traditional methods exactly, a forge is no longer necessary.

Even without a forge, though, the punchcutter in steel will require a small heat-treating setup.

2. Moxon (1683)

Moxon has this to say about the forge:

The making of Steel Punches is a branch of the Smith's Trade; For, as I told you in the Preface to Numb. I. [that is, his first volume of Mechanick Exercises, 1678] The Black-Smith's Trade comprehends all Trades that use either Forge or File, from the Anchor-Smith, to the Watch-maker: They all working by the same Rules, though not with equal exactness; and all using the same Tools, though of different Sizes from those the Common Black-Smith uses; and that according to the various purposes they are applied, &c. Therefore, indeed, a Letter-Cutter should have a forge set up as by Numb. I. But some Letter-Cutters may seem to scorn to use a Forge, as accounting it too hard Labour, and Ungenteel for themselves to officiate at. Yet they all well know, that though they may have a common Black-Smith perform their much and heavy Work, that many times a Forge of their own at Hand would be very commodious for them in several accidental little and light Jobs, which (in a Train of Work) they must meet withal. ( Moxon, Mechanick Exercises (1683) , §. 12. ¶. 1. "Of Letter-Cutters Tools" [p. 88 of the Davis/Carter edition])

Here is Moxon's illustration of a blacksmith's forge from the first volume of Mechanick Exercises (1678) :

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One could say that it shows a typical 17th century blacksmith's forge, but there's a bit of circular logic here because much of what we know about 17th century blacksmithing comes straight out of Moxon.

Moxon's discussions of the practices at the forge (and therefore the tools to be used there) are all in Vol. 1 of Mechanick Exercises. In particular, his discussion of annealing ("Nealing"), hardening and tempering is at the very end of the section on Blacksmithing, on pp. 60-62 as it appears in (at least) the 1703 printing.

For cleaning the scale off of the workpiece prior to tempering, so as to allow the colors which develop on the steel to be seen, Moxon uses "a piece of Grin-stone or Whet-stone." (p. 61)

3. Fournier (1764)

Fournier (1764) does not mention or illustrate a forge explicitly (the furnaces he does illustrate are for alloying typemetal and for typecasting). However, he does discuss annealing punches "in a very hot fire"/"dans un feu ardent" and annealing and probably simultaneously carburizing them in a crucible (Chapter III, "Des poinçons et Countrepoinçons," p. 11; pp. 30-31 of the 1930 Carter translation). In Chapter X, "Hardening" ("De la trempe") he says that:

"The punchcutter provides himself with a furnace or brazier filled with burning charcoal, and puts into it two, three, or four punches at a time, blowing up the fire until they have acquired the colour, not of the whitish flames caused by the puff of the bellows, but of the red heart of the fire. When the punch is brought ot this heat, he takes it with long pointed pincers and plunges it face first to a quarter of its length in cold water and skims over the surface of the water with it thus, to give especial hardness to that part of it, and then plunges it right in." (p. 77 of the 1930 Carter translation, pp. 63-64 of the 1764 original edition).

Carter, in his footnotes, suggests quenching when "cherry-red." Stan Nelson, in his 2016 Wells punchcutting class, observed that Fournier's method of chilling the face of the punch before full quenching was, in his experience, a mistake certain to increase the probability of cracked punches. Indeed, the conventional blacksmith's hardening technique is to plunge the hot punch into the cooling liquid fully (moving it about to keep the formation of an insulating layer of vapor around the punch to a minimum).

For cleaning the scale from the punch after hardening and before tempering, Fournier specifies "une pierre-ponce" / a "pumice stone" (p. 65 of the 1764 edition, or p. 78 of Carter's translation). Later, when he mentions this again, Carter notes that he (Carter) prefers to use an emery stick.

4. Anti-Scale Compounds

Neither Moxon nor Fournier mention the use of any anti-scale compounds in hardening, so I'll delay their discussion until the section on Modern Simple Heat Treating Equipment .

5. Tempering using a Typemetal Pot

Fournier also describes an alternative practice for tempering punches by using a molten typemetal bath as a heat source. The advantage he cites for this method is that the punchcutter's eyes are "thus saved from being dazzled or tired by the heat of the fire":

"This part of the work can be much more readily performed by punchcutters who possess a typefoundry. They plunge the punch into the molten typemetal, holding it with the pincers so that only the cleaned end remains visible. Their eyes being thus saved from being dazzled or tired by the heat of the fire, they can the more comfortably and accurately secure the colour which they desire and which indicates the right degree of temper." (p. 79 of the Carter translation, p. 66 of the 1764 original)

See Stan Nelson's video clip "Hardening Punches and Striking Matrices" from the unfinished film to have been entitled Out of Sorts for a demonstration of this technique using a small metal melting pot generally used for hand typecasting (made in a style such as Fournier might have used).

See the section on "Tempering using a Typemetal Pot" in Modern Simple Heat Treating Equipment for an illustration of this process using a modern electric metal melting pot of the type manufactured for the hobby casting of bullets.

This use of a typemetal bath is related to, but not quite the same as, the older standard industrial practice of using a lead bath for tempering. In the practice described by Fournier, the typemetal bath is simply a convenient non-flame source of heat supplied to one end of the punch. The punch is not fully immersed in it (doing so would make it impossible to see the colors as they develop on the steel). In industrial practice the lead or lead/tin bath is brought to the exact tempering temperature and the part to be tempered is immersed in it:

"The lead bath is commonly used for heating steel in connection with tempering, ... The bath is first heated to the temperature at which the steel should be tempered; the pre-heated work is then placed in the bath long enough to acquire this temperature, after which it is removed and cooled." { Machinery's 11, p. 1156}

(This edition of Machinery's Handbook goes on to provide a table of melting points of lead/tin alloys to assist in the preparation of a lead bath for reaching specific temperatures.)

Fournier's technique, by way of contrast, is nothing more than the use of a convenient (for a typefounder) heat source in traditional blacksmith's color-based tempering.

In modern practice it is convenient to use a small lead melting pot of the style used by amateur bullet casters. The capacity of such a pot and the temperatures it can attain are entirely suitable for this application. See the section on Tempering using a Typemetal Pot in the Modern Simple Heat Treating Equipment section for illustrations.

6. Notes on Current Resources

First - just to get it out of the way - blacksmithing does not mean horseshoeing. The blacksmith is an artisan whose trade is of very general scope (as Moxon says, from the Anchor-Smith to the Watch-Maker, though few watchmakers now would consider themselves blacksmiths). In the period until blacksmithing died out as a significant trade, around the First World War, the blacksmith was the general provider of iron-based tooling to the community. The shoeing of horses is done by the farrier - a specialized and highly skilled occupation. The farrier knows a great deal about horses, but need know just enough about blacksmithing to fit a horseshoe. Of course, and especially in small communities, the blacksmith and the farrier might have been the same person. But the professions are distinct.

Although blacksmithing as a profession has been dead for about a century, we are now living in a kind of a golden age of blacksmithing. Its revival from near extinction began (in the US, at least) with the founding of the Artist-Blacksmith's Association of North America ( ABANA) in 1973 (just five years before the founding of the American Typecasting Fellowship). The blacksmith's work being done today is a fine as any ever done historically, and is often much better informed by a knowledge of the craft and its history.

The aspiring punchcutter who would follow traditional methods completely need not be bound by the information in Moxon and Fournier. The first step would be to join ABANA and become acquainted with the state of blacksmithing today. There are also local ABANA affiliate organizations throughout the countery.

There are many good modern books on blacksmithing. It's best to start with modern sources (because they'll tell you how to set up shop in current conditions) and later work back to classic texts. The best new book is, I think, Lorelei Sims' The Backyard Blacksmith. (Beverly, MA: Quarry Books, 2006. NY: Crestline Books (a division of Book Sales, Inc.), 2009. ISBN-13: 978-0785825678). My favorite introductory series is "Forging Fundamentals: Controlled Hand Forging Lessons" by Dan Naumann and the ABANA Educational Programs Committee. This series first appeared in the newsletter of ABANA, The Hammer's Blow, and is now available online for free.

For resources, get a copy of the catalog of Skipjack Press, and investigate the websites of Centaur Forge and Kayne & Son / BlacksmithsDepot.com .

7. References

{Machinery's 11} Machinery's Handbook, 11th Edition. NY: The Industrial Press, 1943.

Machinery's Handbook is the one remaining standard machine shop reference (sometimes I prefer the earlier American Machinist's Handbook, but it ceased to be current many decades ago). The home shop metalworker would do well to have several editions of this book on the shelf; older editions contain information later omitted, and this missing information tends to be what the smaller-scale home shop operation needs. Here I just picked an edition at random from my shelf - any number of editions contain this same information.

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