USEFUL DATA 



Specifications. Purchasers can greatly influence the prompt shipment of orders 

 [for ordinary "mill shipment" by considering, in the preparation of their specifications 

 and material bills, the factors connected with the methods and internal organization 

 ►of a steel mill. 



Adherence to the Manufacturers' Standard Specifications for Deformed Concrete 

 ^Reinforcing Bars (see page 188), will always facilitate prompt shipment. It is, of 

 course, possible to furnish any class of material that is within the power of the mill to 

 [roll, but where specifications are in any way special the entire order must be 

 made from special heats. The process is one out of the ordinary routine of the 

 mill, billets already prepared cannot be used, and delay in the filling of the order 

 is certain. 



Sizes. It is necessary in the rolling of steel bars, for a mill to finish rolling all of 

 [the bars on its schedule of one particular size before changing the rolls for other sizes 

 of bars. In mill parlance, what is known as a "rolling" extends over a period of several 

 days and an order containing a large number of sizes might be compelled to 

 ►remain in the mill until the completion of the entire rolling, so that where quick 

 ! shipment is desired, the number of sizes on an order should be kept as low as 

 possible. 



In addition to confining the order to as few sizes as may be consistent with the 

 requirements, every endeavor should be made to avoid specifying bars in Yeth sizes. 

 [This is an error frequently made by inexperienced designers in an effort to meet a 

 [theoretical steel area required by their calculations, and can only result in delay at 

 the mill and increased labor and confusion in the field through the necessity of handling 

 ia multiplicity of bars of slightly varying size. 



Lengths. In ordinary mill practice the bars are rolled to lengths varying from 

 100 to 300 feet and sheared into lengths called for by the material bills as they come 

 from the rolls. When, however, the number of lengths are very large and where there 

 are only a small number of bars of one length, the shearing cannot be done as fast as 

 the bars are rolled, consequently the bars must be laid to one side and sheared 

 after the conclusion of the rolling in order that the operation of the mill may not be 

 delayed. It is, therefore, always desirable to keep the number of lengths as low as 

 possible where quick shipment is a necessary requirement. 



The lengths should always be given to the nearest inch as bars are not ordinarily 

 sheared to a greater degree of accuracy. Where it is important that the length 

 called for be exact, a note to this effect should be placed opposite the item on the 

 order. 



Fabrication. For all reinforced concrete structures there is usually a considerable 

 amount of fabricated reinforcement to be furnished. Sometimes this fabrication is 

 done in the field but through the use of special machinery and methods of operation 

 all classes of bending and other fabrication of bar reinforcement can be accomplished 

 with greater accuracy and advantage in the shop than in the field, and in the 

 majority of instances it is advisable for the purchaser to specify "shop fabrica- 

 tion." 



Accompanying all orders for fabricated material there should be fiirnished in addi- 

 tion to the list of number of pieces, size and length of bar, a sketch of each differently 

 fabricated piece with the dimensions plainly marked thereon. A few of the details 



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