Sharpening: Sharp cutting tools makes a job easier and less dangerous, because Less pressure is needed to do work. Finish sharpening: Stones are used to put a fine or “keen” edge On cutting tools such as knives. Some tools like axes are finished sharpen with A single cut file. Hand saws are also sharpened with a set of small Files.

Types of cutting edges: Single inclined: Wood chisel Double inclined: Cold chisels Straight edge: Straight line Concave: “hollow” ground Inward curve made By a grinder. Convex: Outward curve.

Hardness: Carbon in steel allows it to be made hard, or soft. Annealing is cooling a piece of hot metal slowly. It softens The metal. Tempering is the hardening of steel. Heating the metal to a Certain temperature for a certain length of time “sets” the carbon At a certain point in the metal. When sharpening tools with a grinder you have to make sure That you do not get them too hot or you will affect the Hardness of the metal.

Sharpening: “True” or “joint” the cutting edge to remove any nicks. Follow the following angles when grinding.

Sharpening specific tools: Wood chisels: Are sharpened on one side to a 25 degree concave Angle. This is done by moving the metal back And forth across the grinder at the correct angle. Cold chisels: Are sharpened on both sides to a total angle of 70 Degrees. This is done by moving the metal back And forth across the grinder at the correct angle. The sides of the cutting edges must be equal. Center punches: Are sharpened at a 60 degree angle. This is done By “twisting” the metal against the wheel while Sharpening. Twist drill: Are sharpened at a 60 degree angle. This done by Starting at the cutting edge at the proper angle against The wheel. Lightly push in twist the drill as you lift Up. This gives the 12 degree rake angle. Both side Must be equal.

Angles of a twist drill One type of tool gauge