BULLETIN 527, U. S. DEPARTMENT OP AGRICULTURE. 



length of the board. As the square forms a right angle, the short side 

 ■will then be at right angles to the sides of the board; consequently, 



a line drawn on the board along this short 

 side will be at right angles to the side of 

 the board. The try square is used for 

 squaring up boards, as shown in figure 7, 

 and also for testing surfaces and testing 

 angles. Figures 15 and 16, pages 6 and 7, 

 show these operations. 



The hammer has two uses — to drive nails, 

 and to pull nails. When driving nails, grasp 

 the handle near the end farthest from the 

 head; you 

 can. strike 

 a more ef- 

 fective blow than if you grasp it 

 near the other end. When pulling 

 nails, the hammer acts as a lever; 

 it is surprising how much puL 

 ling force is exerted on the nail. 



Fig. 7. — Squaring up a board with 

 a try square. 



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Fig. 8. — Plane iron, plane-iron screw, and cap 

 iron. 



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 rfPJUSTMENT, 



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 Fig. 9.— Parts of a plane. 



The plane is used to smooth 

 surfaces. The jack plane is 

 theonemost commonlyused. 

 The plane iron is the cutting 

 part of the tool. Figure 8 

 shows the plane iron, the 

 plane-iron screw, and the 

 cap iron, and figure 9 shows 

 a cross section of a plane 

 with the different parts 

 clearly indicated. With a 



plane before you, examine all these parts. 

 When a plane is properly adjusted the 

 plane iron projects the same distance from 

 each side of the throat. The adjustment is 

 tested by sighting, as shown in figure 10, 

 and by feeling with the fingers to see that 

 the edge projects equally on each side. 



The marking gauge is used to gauge, or 

 mark, a line parallel to one edge of a 

 board. To set the gauge, hold it point 

 side up in the left hand, and with the rule 

 in the right hand place the end of the rule 

 against the gauge block and see that the 

 measurement desired on the rule is at the point of the gauge, as shown 

 in figure 11. Tighten the set screw, and the tool is ready for use. 



Fig. 



10.— Sighting to adjust 

 plane. 



