116 



THE SAWMILL 



(g) Inserted tooth circular saws. 



1. The insertion into each socket of the rim consists of a holder and of a chisel point. These points 

 are e.xtremely hard ; still they can be filed and swaged with the help of specially- constructed files. 

 It does not pay, however, to spend much time in filing since new points are cheap, and since 

 they are readily inserted with the help of a special wrench. 

 Points are oiled before being inserted. 



When renewing one individual point be sure to have it dressed down to correspond to the 

 line of old points. 



If the saw guide is not properly adjusted, it may touch the holder and smash the saw. 



Small inserted tooth circular sawmill with carriage. Whelaiid Machine Works, Chattanoog'a, Tenn. 



2. Advantages of inserted tooth saw are : - 



Temper of the teeth can be harder than that of the saw itself. 



Less experience is required for dressing a saw. 



Less filing and gumming. 



Less saw repairs in backwoods. 



Diameter of saw remains unchanged during its use. 



3. Disadvantages of inserted tooth saw are:- 



The saw kerf is very heavy. 



The teeth are large and hence few, so that feed must be comparatively slow. 

 The price of the inserted tooth saw is higher than that of the solid tooth saw. 

 The best makes are the Atkins, Simonds, and Disston saws, 

 (h) The double circular saw. For big logs and high speed a double circular saw must be used. 

 The width of the widest board which a single circular saw may cut equals radius minus three inches. 

 Hence much valuabK' material is wasted in the common circular sawmill when heavy logs are sawed. 

 The double circular saw usually shows an under or lower saw of 56 inches or 60 inches and an 

 upper saw of 30 inches or 36 inches diameter. 



A hanger top saw can be added readily to any single saw. Both saws should have the same speed 

 at rim. The rotation of the top saw should be the reverse of that of the main saw, so as to prevent the 

 saws from throwing sawdusi one in the other's kerf. 



