Grind a cold-chisel so that its cutting edge is rounding and not hollow, as it is often made. A rounded chisel is stronger and cuts smoother. A hollow chisel has no useful place as a chipping-tool.

Fig. 1

Fig.2. Cold Chisels

To Harden Chisels Cold

Heat the chisel to a distance about equal to its width, immerse it about half that distance in the water hold it still about four seconds, suddenly dip it a little deeper, and then withdraw. Brighten one flat surface with a piece of grindstone or an emery-block; then brush the band or a piece of waste over the brightened surface to remove the false color, and finally cool out in the water, when the clear blue color appears.

To Hold Chisels Cold

Hold a cold-chisel firmly to its cut, without removing it at every blow. This will increase its effectiveness, and decrease its Liability to break from a foul blow.

To Remove Burrs From The Heads Of Chisels Cold

When the head of a cold chisel is burred over from use, rest the head upon a block of iron, and strike the burrs from the under side, and they will break readily and easily off.

Use Of Cold Chisels

These should be kept thin at the cutting end, which saves time and entails less labor in using.