CLASSIFICATION OF MATERIAL. 427 



(*) Plates checkered. 

 ($') Plates buckle. 

 Angles (a) Having both legs 6 in. wide or under. 



(b) Having either leg more than 6 in. in width. 



(c) Having both legs less than 3 in. in width. 

 Channels and I- Beams 



(a) Channels and beams up to and including 15 in. in depth. 

 (6) Over 15 in. in depth. 



If Bethlehem sections are used distinguish between "Bethlehem Special I-Beams" and 

 "Girder Beams," and also regarding depths as above. 



Zees. 



Tees. 



Rails (Separate rails under 50 Ib. per yd., rails over 100 Ib. per yd., and girder rails). 



Rail Splices. 



Iron Castings. 



Steel Castings. 



Nuts. 



Clevises and Turnbuckles. 



Pins, rounds from 3 in. diameter to 6| in. in diameter. 



Forgings, rounds over 6J in. in diameter. 



Bronze, Lead, etc. 



Rivets and Bolts. 



Rivet Heads. Where the estimate is made from shop drawings the actual number of rivet 

 heads shall be determined. The weight of rivet heads in per cent of the total weight of the other 

 material is about as follows: Purlins, girts and beams, 2 per cent; trusses and bracing, 4 per cent; 

 plate girders and columns of 4 angles and I pi., 5 per cent; plate girders and columns with cover 

 plates, 6 per cent; box girders or channel columns with lacing, 7 per cent; trough floors, 8 to IO 

 per cent. 



The rivet heads in highway bridges may be taken at 5 and 4 per cent of the total weight 

 of steel exclusive of fence and joists for riveted and pin-connected trusses, respectively. 



Bolts are usually taken off in the estimate when they occur, and entered as rivets. When 

 bolts are under 6 in. in length, include bolts under the item " Bolts and Rivets." When over 

 6 in. in length, put the bolts under "Bars." 



Miscellaneous Materials. Corrugated Steel. Always give the number of gage, whether 

 painted or galvanized, and whether iron or steel. This remark also applies to louvres, flashing, 

 ridge roll, gutters and conductors. State whether corrugated steel is for roofing or siding. Roofing 

 shall be estimated in squares of 100 sq. ft., adding three feet on each end of building to the distance 

 c. to c. of end trusses to allow for cornice. Allow one foot overhang at eaves. Siding shall be esti- 

 mated in squares of 100 sq. ft., adding one foot at each end of building to allow for corner laps. 



Louvres shall be estimated in sq. ft. of superficial area, stating whether fixed or pivoted. 



Flashing shall be estimated in lineal feet and shall be taken off over all windows where corru- 

 gated sheathing is used on the sides of building, and under all louvres and windows in ventilators. 



Ridge roll shall be estimated in lineal feet, adding one foot to the distance center to center 

 of end trusses. Ridge roll is usually taken off the same gage as the corrugated steel roofing. 



Gutters and conductors shall be estimated in lineal feet, the conductors usually being spaced 

 from 40 to 50 ft., depending upon the area drained. 



Circular ventilators shall be estimated by number, giving diameter and kind, if specified. 



Stack collars shall be estimated by number, giving diameter of stack. 



Windows shall be estimated in sq. ft. of superficial area, taking for the width the distance 

 between girts. State whether windows are fixed, sliding, pivoted, counter-balanced or counter- 

 weighted. State kind and thickness of glass and give list of hardware, and any thing else of a 

 special nature. 



