CUTTING TOOLS 23 



The iron and cap were held in position by a wooden 

 wedge, which was driven in by a light blow of the 

 hammer. The workman removed the iron and wedge 

 by turning the plane upside down and striking the 

 forward part a light downward blow on the bench, 

 while the thickness of the shaving was increased by 

 a light tap on the plane iron. 



One of the chief objections to the wooden plane was 

 its liability to wear and warp, so that it became neces- 

 sary to straighten, or joint, the face. No such diffi- 

 culty is encountered in the d 

 iron-bodied plane. \/^ incorrect { 



15. The Chisel. The chisel #**-" * 



is one of the simplest forms .^ ? 



^*^*a Correct I 



of cutting tools. The size of ^ l 



the angle a depends on the FlG . 29 . Cutting Angle of chisel 

 kind of material to be cut. 



A chisel for cutting wood must be sharpened to an 

 angle of from 30 to 35 degrees. 



By careless sharpening an extra bevel is sometimes 

 formed, as shown at b. 



The cutting angle is then no sharper than if ,the 

 chisel were shaped like that shown by dotted lines, 

 and care must always be taken when sharpening to 

 keep the line cd straight, so that angle a will be the 

 real cutting angle. 



