Secondary vertical posts may be made of two rolled channels laced, or of four angles in the form of an I with a single line of lacing. These secondary vertical posts should be riveted to the top chords instead of being pin-connected thereto, as in the case of the main vertical posts.

The channels of vertical posts may have their flanges turned either inward or outward, as desired, or so as best to suit the general detailing of the truss.

Stiff bottom chords and inclined web-struts may be made of either two channels with two lines of lacing or of four angles with one line of lacing, the use of trussed eye-bars for struts being prohibited.

Upper lateral struts, overhead transverse struts, and web-stiffening struts shall preferably be made of four angles with one line of lacing. In case, however, the said angles be spaced very far apart, as in lateral struts connecting deep top chords, they are to be placed on the corners of a rectangle, with their legs turned inward, and laced on all four faces of the box strut thus formed.

Eye-bars are to be used for all bottom chords and main diagonals that do not require to be stiffened.

Counters, when employed, can be of either rounds, squares, or flats. These and all other adjustable members are to have their ends enlarged for the screw-threads (unless soft steel, cold-pressed threads be used), so that the diameter at the bottom of the thread shall be one eighth (1/8) of an inch greater than that of the body of a round rod of area equal to that of the adjustable piece.

Diagonals for upper lateral systems and vertical sway-bracing shall, preferably, be built of four angles in the form of an I, with a single line of lacing; but for structures where this section would involve an extravagant use of metal, two of the angles, one at the top and one at the bottom, may be omitted, thus making each strut consist of two angles laced, provided, of course, that where the struts cross they shall be rigidly connected by two plates of ample size. This unbalanced section for such diagonals is to be avoided whenever it can  be  done  without  undue  use  of  metal.  In no case, though,