10 STANDARD SPECIFICATIONS 



bers shall not exceed four diameters of the rivet for a length 

 equal to two times the width of the member. 



35. Edge Distance of Rivets. The minimum distance from 

 the center of any rivet hole to a. sheared edge shall be IV' for 

 I" rivets, 1J" for f " rivets, 1J" for f " rivets, and I" for V' rivets, 

 and to a rolled edge, except in flanges of I-beams and channels, 

 H" > li" 1" an d i" respectively. The maximum distance from 

 any edge shall be eight (8) times the thickness of the outside 

 plate, but shall not exceed 5 in. 



36. Tension Members. In calculating the net area of tension 

 members the area of rivet holes must be deducted, assuming 

 the diameter of the hole J in. larger than the nominal size of 

 the rivet. 



Main tension members shall be composed of sections placed 

 symmetrically about the central plane through the truss. Second- 

 ary tension members may be made of a single shape. (Par. 15.) 



Pin-connected riveted tension members shall have a net 

 section through the pin hole 25 per cent in excess of that through 

 the body of the main member. The minimum net section hack 

 of the pin hole, parallel to the axis of the member, shall not be 

 less than that through the body of the main mcinlx-r. 



37. Eye-bars. Heads of eye-bars si mil be forged and so 

 proportioned as to develop the full strength of the bar. (Par. 

 43.) 



The eye-bars shall be placed in the truss so as to be. as nearly 

 as possible, parallel to its central plane, the maximum incli- 

 nation being limited to 1 in. in 16 ft. 



38. Rods. The minimum size of bracing rods, or laterals, 

 shall be J in. in diameter and they shall be upset at the screw ends. 

 The minimum size of sag rods shall be Jin. in diameter, but these 

 need not be upset. 



39. Compression Members. Main compression members shall 

 be* composed of sections placed symmetrically about the central 

 plane through the truss. Sub-struts may be made of - a single 

 shape. (Par. 15.) 



No compression member shall have a length exceeding 120 

 times its least radius of gyration, except those used for wind and 

 lateral bracing, which may have a maximum length of 140 times 

 their least radius of gyration. 



40. Tie-Plates. The open sides of compression members 



