by J.M.Drew St. Paul Publishing Company 1918
- HOME -Farm Blacksmithing
A in Fig. 34 shows an ordinary blacksmith's flat drill. B is a drill with a twisted end. This latter will cut faster and easier than a flat drill but cannot be refined by hammering in the same manner as a flat drill and therefore cannot be made to stand as much abuse as the flat drill. To make a flat drill, use steel of about the same carbon as for cold chisels. Draw down, round, to a size somewhat smaller than the drill needed, then flatten out the end as at C a trifle larger than necessary so as to allow for filing or grinding down to size. Out off the corners on the hardy, then allow cooling, and filing to shape as shown in the cut.
The twisted end drill is started in the same manner as the flat drill. After flattening out the end as shown at C, the twist is started in the end by using a small pair of tongs, or by holding the end in the corner of the vise while the drill is turned. After the twist is started the edges are upset by using a light hammer and striking quick, light blows; holding the steel meantime in such position that the hammering will increase the twist.
To temper a drill, if it is a large one, use the same method as in tempering the cold chisel, already described, excepting that it should be made a little harder (purple, instead of blue). In the case of a small drill, heat to a dull red and cool off entirely, then, after polishing, heat up to the proper color by holding against J. piece of hot iron or by pinching with a pair of hot tongs. The average farm blacksmith would better buy twist drills of small sizes, and make the larger ones as he needs them.
The sharpening of plows is a job which the farm blacksmith will be called upon to do very often, and while it is not particularly difficult work, still it calls for a knowledge of steel, and a practical knowledge of how a plowshare should be shaped to run well. For sharpening an ordinary plow share in case one man has to do the work alone, a round faced hammer weighing about 2 ½ or 3 pounds is the proper tool to use. With it the edge of the share may be drawn out by hammering on the upper side while the lower side is kept straight by being held flat upon the anvil. For quick work in drawing out a very dull or thick share, especially when a striker is at hand to help, the share is turned bottom up and the edge drawn out by using the cross pein of the sledge.
The greatest care must be used not to burn the edge of the share while heating. He is a very careful blacksmith who never burned the edge of a plow share. In drawing out the edge of the share near the point, the point itself is very apt to be bent around too far "to land." This condition is not easy to avoid nor to remedy. It will not do to rest the edge against the anvil to drive the joint back, for this would dull the edge. Usually the edge is rested on a hardwood block while the point is being driven back. This accomplishes the purpose without spoiling the edge. The welding on of new points where old ones have worn too short is a piece of work which is apt to give trouble to the young blacksmith when he tries it for the first time.
A new point for a share should be made of plow steel, a piece cut from an old share is good, and not from a rasp or from any steel high in carbon as such will give too much trouble in welding. The edges should be drawn down thin, and after placing on the point of the share the new piece and the old point should be covered with borax and iron filings. The welding should be done in the fire, at least the first part of it. After starting the weld in this way it may be finished on the anvil; the end cut off to the proper shape, the edge drawn out sharp and the land side squared up. In making a weld of this kind it is necessary to heat very slowly in order that the two parts may reach the welding heat at the same time. Quick heating would cause the thin new point to burn before the larger part got hot enough to weld. No amateur smith should attempt this job until he has had considerable experience in welding steel. If he is at all uncertain of his ability to manage a heat of this kind, he should practice on two small pieces of plow steel before running the risk of burning a plow share. To harden a plow share which is made of such soft steel that it cannot be tempered in the ordinary way, heat to a uniform light red heat and sprinkle over the entire upper surface powdered red prussiate of potash; this will melt and flow over the surface of the steel, when it should be plunged into cold water or brine. For use in land containing no solid stones it is usually safe to harden the plow share quite hard. This, in case of shares made of good steel, may be done by simply heating to a full red color and plunging into water or brine. It is best to plunge the share in thick side first. Fig. 37 shows a handy tool for holding the so-called slip-shares. It is a convenience in holding them while sharpening and it prevents their warping. The shares which may be taken off the plow with the landside and brace on are the most convenient to handle in sharpening, and give no trouble by warping out of shape.