Modern Blacksmithing Rational Horse Shoeing and Wagon Making

with rules, tables, recipes, etc., useful to manufactures, blacksmiths, machinists, well-drillers, engineers, liverymen, horse-shoers, farmers, wagon-makers, mechanics, amateurs and all others who have occasion to perform the work for which this book is primarily intended. by J.G. Homstrom 1901

How to Harden a Plow

The share is of soft center steel, harden as follows: First,heat the whole point to a very low red heat; then turn the share face down, with the heel over the fire, and the point in suc)l a posi. tion that it is about two inches higher than the heel. This will draw the fire from the heel along towards the point, and the whole length of the share will be heated almost in one heat. Be sure to get an even heat, for it will warp or crack if the heat is uneven. When the share has a moderate red heat take it out, and you will notice that it is sprung up along the edge. This is the rule, but there are exceptions, and the share is then sprung down. In either case set it right; if sprung up set it down a little under the square; if sprung down set it a little over the square. You cannot with any success set it by a table or leveling block, because this will, first, cool off the edge, second, it must be either over or under the square a little. Therefore, you must use your eye and set the share with the hammer over the anvil. This done, hold the share over the fire until it has a low red heat, as stated before; then plunge it into a tub of hardening compound, such as is sold by the traveling man, or sprinkle the share with prussiate of potash and plunge it into a barrel of salt water.

You will notice that the share will warp or spring out of shape more in the heating than it does in the cooling, if the heat is right. Some smiths never look at the share when hot for hardening, but simply plunge it into the tub, and then they say it warped in hardening, while it was in the heating. If the share is too hot it will warp in cooling also.