188 PRACTICAL STRUCTURAL DESIGN 



First divide / by 8 = 24,000 -i- 8 = 3000. 

 Then M = 3000 Ad 



M 



= 3000 



A = 0.7854 <P, therefore Ad = 0.7854 d\ 

 _ 80,000 

 ~ 0.7854 x 3000' 



80,000 



Many tension members in steel work are made of round rods 

 or rectangular eye bars. The ends are fastened to the frame by 

 means of pins passing through loops or yokes or eyes. The area 

 of the main part of the member is found by dividing the total 

 tension by the allowable fiber stress. The thickness of the loop, 

 the yoke or the eye is determined by the required bearing area 

 on the pin. If the enlarged section on the end to receive the pin 

 is welded to the member the stress used should be low to allow 

 for imperfections in the welding. If the members are purchased 

 from the mills already welded they should be purchased under 

 very rigid specifications. The use of clevises, turnbuckles and 

 sleeve nuts permits tension members to be lengthened and 

 adjusted for length. 



In the Carnegie Pocket Companion, 1913 edition, all the in- 

 formation the designer needs about the sizes of screw threads, 

 bolts, eye bars, loop rods, clevises, turnbuckles and sleeve nuts 

 is found on pages 112 to 122 inclusive, 215, 218, 219, 223. 



Similar information is found on pages 322 and pages 331 to 

 357 inclusive in the 1914 edition of the Cambria Steel Hand Book. 

 In the 1916 edition of Jones & Laughlin, Standard Steel Con- 

 struction, this information is on page 246 and on pages 255 to 268 

 inclusive. The Lackawanna Steel Company Hand Book contains 

 similar information on pages 339 to 363 inclusive. 



Rivets and Rivetting 



A rivet is a piece of metal which connects together two or 

 more pieces of metal. In structural work rivets are made of soft 

 steel. A head is formed on one end of a rivet when it is made and 

 when used the rivet is heated and the surplus length projecting 



