This section is from the book "Machinery's Shop Receipts And Formulas", by The Industrial Press. Also available from Amazon: Machinery's Shop Receipts and Formulas.
Cover the steel with fire clay, and heat to a red heat. Then allow the steel to cool over night in a furnace or forge. This method will prove satisfactory when other means fail. Samuel H. Owens.
Smear the iron or steel with tallow, and heat slowly in a charcoal fire until it is a dark red. Allow it to cool itself. This method is all right for very hard tool steel. R. B. Casey.
Schenectady, N. Y.
Heat slowly or rather evenly to a dull red heat. Put it in a dark place or corner, box or barrel, until all signs of red have just disappeared, then quench in water, taking care to hold it still. When annealing flat stock, heat evenly and thoroughly, place between two planed pine boards on an ash heap and cover with ashes. By this method the charcoal is produced, so to say, automatically. Wm. B. Brooks.
New Kensington, Pa.
To make a mixture for protecting finished copper pieces which require annealing mix to a thick consistency white cold water paint and alcohol and apply to the copper with a brush. Allow the mixture to dry and then heat to a low red by dipping into pure melted lead at the required temperature. Cool in air or water, preferably the latter. L. C. Carr.
To anneal steel having hard and soft spots, remove the scale, and heat slowly and evenly to a little above a dark red. Immerse in fresh water until almost cool. Heat immediately to a dark red and anneal in the usual way. C. P. Emerson.
In working zinc the greatest loss is on account of the zinc cracking and being too brittle to handle to advantage. It is surprising to find how very few mechanics understand the annealing or malleablizing of same. The following will be found unfailing: Heat in oil to about 500 degrees F. and plunge in hot soda water, which works the double operation of drawing the zinc to the proper degree and at the same time cleanses the surface from the oil.