30 Bulletin *i18, u. s. department -of AGRicuLTtrRE. 



guides the saw in a measure, and should be filed stjuare across. If 

 a saw is frozen, alwa3^s thaw it out before attempting to set the 

 teeth. 



The greatest wear on the saw is on the under edges of the teeth. 

 File nearly to an ed.oe, but not quite, leaving a short bevel of one- 

 thirty-second of an inch wide on the underside of the point. But 

 in no instance file to a fine point or thin wire edge. Do nearly all the 

 filing on the underside of the teeth and see that they are well spread 

 (swedged) at the points. File square across and have them pro- 

 ject alike on both sides of the saw. 



On crosscut saws, bevel the front of one tooth one way and the next 

 tooth the opposite way. File rip saws square in front; use a light 

 hammer in sweclging, from three-fourths to 1 pound, holding the 

 swedge so that the teeth will spread at the points. Swedge out wide 

 and then dress down to the required width. Most cases of saws 

 " crumbling '" are caused by the use of too delicate a swedge. In 

 such cases the corners of the tooth are not strong enough to stand 

 the cutting strain. 



Be sure to have a side file for jointing the teeth and keeping all 

 the points the same length on each side of the saw. 



The cost of changing solid-tooth saws into inscrted-tooth saws is 

 usually $1.50 per tooth plus one-half the list price of a solid-tooth 

 saw of the same size. 



Inserted teeth. — It is not economical to spend much time filing in- 

 serted teeth, because new points are cheap and arc quickly inserted. 

 It should never be necessary to swedge the bits. Light filing on the 

 underside is the only thing required to keep them sharp, because the 

 cutting point tapers graduall}^ and allows plenty of clearance, even 

 though the point is worn almost entirely away. Swedging is likely 

 to injure the shoulders and sockets, unless great care is taken in the 

 operation. Use a light 1-pound hammer and hold the swedge so that 

 the teeth will be spread a.t the point. Have a cup of oil, together 

 with the teeth, placed conveniently near you at the- back of the saw. 

 Take the wrench and plajce the pins in the holes in the shank, turning 

 the latter so that the hook projects sufficiently to receive the bit. 

 Pick up a tooth with the other hand and dip the grooved segment 

 into the oil, then place it in position and hold it firmly and evenly 

 with the sides of the blade, and at the saraie time press the wrench 

 downward until the shank fits into its place. The inserted teeth 

 are exact in width and the spread uniformly good. If extra nice 

 work is desired, try a gauge on the side of each tooth. If any are 

 found to project a trifle too far, reduce them with a side file, being 

 careful to preserve the same relief" of the corner. No flat surface 

 should be allowed on the side of the teeth, which must be relieved 

 from the very point. 



