COMMON HAND-TOOLS 



271 



STRAIGHT DG CVf?VO 0G 



FIG. 133. A Scraper. 



light straw color. After grinding, the edge should be rubbed 

 down on an oil stone. On one end of the scraper the edge 

 may be slightly curved as shown. 



Another type of scraper with a wood handle, sometimes 

 called a graver, is used for work 

 in lathes and for hand-work on 

 round corners. A good scraper 

 can be made from an old file. 

 When work is to be scraped it must be first rubbed or 

 tested on a standard and perfectly flat plate called a sur- 

 face plate. The method used is to put a very thin coat- 

 ing of red lead mixed with oil on the surface plate. The 

 high points which must be removed first, are shown by small 

 red spots on the surface of the block. When the work is 

 heavy and awkward to handle the surface plate may be 

 rubbed on it. Care is required to rub 

 over the whole plate evenly to prevent 

 wearing and dishing the center. 



310. Kinds of Drills. Drill points 

 are used for boring small holes in 

 wood, iron, brass, or other materials. 

 There are three kinds of drills; flat, 

 straight-fluted, and twist drills (Fig. 

 134). The flat drill can be used for 

 almost any material, but does not cut 

 so rapidly as either of the others. It 

 is best suited for use on thin metals 

 and on tile. The straight-fluted drill 

 can be used advantageously on wood 

 and the softer metals. It is especially satisfactory for drilling 

 holes all the way through a piece of material, as it does not 



(Copyrighted by Millers 

 Falls Co.) 



(a) (6) (C) 



Straight- Twist Flat 

 Fluted 

 FIG. 134. Drill Points. 



