64 



STEEL ROOF TRUSSES AND MILL BUILDINGS. 



CHAP. I. 



130. Thick Material. Full-sized material for eye-bars and other steel i in. thick and over, 

 tested as rolled, shall bend cold 180 degrees around a pin the diameter of which is equal to twice 

 the thickness of the bar, without fracture on the outside of bend. 



131. Bending Angles. Angles f in. and less in thickness shall open flat and angles | in. and 

 less in thickness shall bend shut, cold, under blows of a hammer, without sign of fracture. This 

 test will be made only when required by the inspector. 



132. Nicked Bends. Rivet steel, when nicked and bent around a bar of the same diameter 

 as the rivet rod, shall give a gradual break and a fine, silky, uniform fracture. 



133. Finish. Finished material shall be free from injurious seams, flaws, cracks, defective 

 edges, or other defects, and have a smooth, uniform, workmanlike finish. Plates 36 in. in width 

 and under shall have rolled edges. 



134 Stamping. Every finished piece of steel shall have the melt number and the name of 

 the manufacturer stamped or rolled upon it. Steel for pins and rollers shall be stamped on the 

 end. Rivet and lattice steel and other small parts may be bundled with the above marks on an 

 attached metal tag. 



135. Defective Material. Material which, subsequent to the above tests at the mills, and 

 its acceptance there, develops weak spots, brittleness, cracks or other imperfections, or is found 

 to have injurious defects, will be rejected at the shop and shall be replaced by the manufacturer 

 at his own cost. 



136. Allowable Variation in Weight. A variation in cross-section or weight of each piece of 

 steel of more than 2| per cent from that specified will be sufficient cause for rejection, except in 

 case of sheared plates, which will be covered by the following permissible variations, which are to 

 apply to single plates. 



137. When Ordered to Weight. Plates I2| Ib. per square foot or heavier: 

 (a) Up to 100 in. wide, 2| per cent below or above the prescribed weight. 



PLATES J INCH AND OVER IN THICKNESS. 



PLATES UNDER \ INCH IN THICKNESS. 



(6) One hundred in. wide and over, 5 per cent above or below. 



138. Plates under 12 1 Ib. per sq. ft.: 



(a) Up to 75 in. wide, 2 per cent above or below. 



(&) Seventy-five in. and up to 100 in. wide, 5 per cent above or 3 per cent below. 



(c) One hundred in. wide and over, 10 per cent above or 3 per cent below. 



139. When Ordered to Gage. Plates will be accepted if they measure not more than .01 

 in. below the ordered thickness. 



140. An excess over the nominal weight, corresponding to the dimensions on the order, 

 will be allowed for each plate, if not more than that shown in the preceding tables, one cubic inch 

 of rolled steel being assumed to weigh 0.2833 Mb. 



