40 BULLETIN "718, U. S. DEPARTMENT OF AGRICULTURE. 



should never exceed twice the gauge of the tooth, and that more set 

 is needed in long saws and for softwoods than for short saws and 

 hardwoods. 



The side file should be used to remove any feather edge or burr 

 left in filing and to even up the set perfectly. This can be done while 

 the saw is in the vise or filing clamp. Place an 8-inch mill bastard 

 file in the recess on the side file and tighten the screws holding the 

 file. Be particular that the saw is held firmly in the clamp. Pass the 

 center of the file lightly against the teeth until the burr is removed 

 and the set evened up. Care should be taken not to use the side file 

 more than is necessary to remove the feather edge and even up the 

 set. The wrench may be used to lessen the set if necessary, but should 

 never be used to set the teeth. This should be done only with a 

 hannner upon the setting block or on any hard and slightlj^ beveled 

 surface. Xotice carefully the manner in which the saw is filed when 

 new, and file as nearly as possible along the same lines. 



To secure the best results, the saw should be sharpened after being 

 set. If it is desired merely to swage the point of the rakers, this may 

 be done with a light blow of the hammer on the extreme point of the 

 raker teeth. A raker gauge, the flange of which rests on the points 

 of the cutting teeth, is useful for inexperienced saw filers. The filer 

 can reduce the projectiTig points with the file until stopped by the 

 edge of the gauge. In this manner tooth after tooth can be rapidly 

 and correctly reduced to an even length by any unskilled operator. 



A saw now on the market has the teeth in groups of three, the 

 center one a cutting tooth and the ones on either side rakers. The 

 cutting teeth are set, but the rakers are not. The saw can be used 

 for any kind of timber, the teeth varying in size according to the 

 work they are to do. The raker teeth are beveled to form a sharp 

 point and have cutting edges, thus forming a combined raker and 

 cutting tooth. This is the distinctive feature of the saw. 



In ripping, the bottom of the kerf is cut sideways. This causes 

 the saw to rip faster and easier than the old-style ripsaw, which 

 works chisel fashion and has to cut the wood almost square across the 

 grain. The set which is given the cutting teeth assists the rakers 

 very materially by cutting the kerf a little wider than the raker teeth 

 and by cutting the sides of the kerf perfectly smooth. This causes 

 the saw to run freely and easily. Ripping is done by cutting, instead 

 of tearing, as is the ?ase with the old-style ripsaw. 



In crosscutting, the teeth cut in four different lines in the kerf. 

 In this way the fibers are cut in small, short pieces and are much 

 easier to break out than if they extended clear across the kerf. As 

 all teeth are of the same length they loosen the sawdust clear to the 

 bottom of the kei-f, thus removing much friction that occurs where 

 a square raker tooth is used. This style of tooth works equally well 



