OCR Text |
Show Drilling Hard Steel Not Difficult by New Plan In preparing a drill to be used on hard steel, the drill should be heated to an even red heat, the scale removed re-moved and the tip of the drill be touched to a drop of quicksilver and then be quenched in water. After this treatment th; drill will go thrcugh the hardest steel without trouole. A simple method of tempering temper-ing small tools quickly Is to heat them red hot and then thrust them Into a potato, after which they should be drawn to the correct temper to remove re-move bvittloness. |