16 



Reamed 

 Holes 



Accuracy of 

 Punching for 

 Reamed Work 



Reaming 



after 



Assembling 



Accuracy of 

 Reaming 

 and Drilling 



Drilled Holes 



Field 

 Connections 



Shop 

 Assembling 



Match 

 Marking 



Abutting 

 Joints 



Fit of 

 Stifteners 



Splice Plates 

 and Fillers 



Floor Beams 

 and Stringers 



144. In sub-punched and reamed work, the holes shall be punched 3/16 inch smaller, 

 and, after assembling, reamed 1/16 inch larger than the nominal diameter of the rivet. 

 The diameter of the punch used shall be 3/16 inch smaller than the nominal diameter 

 of the rivet, and the diameter of the die not more than 3/32 inch larger than the diameter 

 of the punch. 



145. Reaming shall be done with twist drills without the use of any lubricant. 

 Hand-held reamers shall preferably not be used. Outside burrs shall be removed with 

 a tool making a 1/16 inch fillet. 



146. In sub-punched and reamed work, the punching shall be so accurately done 

 that, after assembling and before reaming, a cylindrical pin 1/8 inch smaller in diameter 

 than the nominal size of the punched hole may be entered, perpendicular to the face of 

 the member, without drifting, in at least 75 per cent, of any group of contiguous holes 

 in the same plane. If this requirement is not fulfilled, the badly punched pieces shall 

 be rejected. If 5 per cent, of the holes will not pass a pin 3/16 inch smaller in dia- 

 meter than the nominal size of the punched hole, this shall be cause for rejection. 



147. Reaming shall be done after the pieces forming a built member are assembled 

 and so firmly bolted together that the surfaces are in close contact. Before riveting 

 they shall be taken apart, if necessary, and any shavings removed. When it is necessary 

 to take the members apart for shipping or handling, the respective pieces reamed to- 

 gether shall be so marked that they may be re-assembled in the same position in the 

 final setting up. No interchange of such reamed parts will be permitted. 



148. When holes are reamed or drilled, after assembling of parts, 85 per cent, of 

 any group of contiguous holes in the same plane shall, after reaming or drilling, show 

 no offset greater than 1/32 inch between adjacent thicknesses of metal. 



149. Holes in flanges of rolled beams and channels and in all steel of greater thick- 

 ness than 3/4 inch shall be drilled from the solid. Outside burrs shall be removed from 

 drilled holes. 



150. All field connections, except those in lateral, longitudinal and sway bracing 

 and connection plates for same, shall be reamed or drilled to approved steel templates, 

 otherwise the connecting members shall be assembled in the shop and then reamed and 

 drilled. 



151. The parts of riveted members shall be well pinned and firmly drawn together 

 with bolts before riveting is commenced. The drifting done during assembling shall be 

 only such as to bring the parts into position, and not sufficient to enlarge the holes or 

 distort the metal. Surfaces in contact shall be painted before being assembled. Bolts 

 in field connection holes shall be left in place. 



152. Connecting parts assembled in the shop for the purpose of reaming or drilling 

 holes in field connections shall be match marked, and a copy of diagram showing such 

 marks shall be furnished to the Engineer. 



153. Abutting joints in compression members and girder flanges, and, where so 

 specified on the drawings, in tension members, shall be faced and brought to an even 

 bearing. Where joints are not faced, the opening shall not exceed 1/8 inch. 



154. Stiffeners under the top flanges of deck girders and at all bearing points shall 

 be milled or ground to bear against the flange angles. Other stiffeners must fit suffi- 

 ciently tight against the flange angles to exclude water after being painted. 



155. Fillers and splice plates shall fit within 1/4 inch at each end, unless otherwise 

 instructed. 



156. The ends of all floor beams and stringers shall be milled to exact length after 

 the end connection angles have been riveted in place. Milling is to be done in such a 

 manner that the ends of all main material, as well as the faces of connection angles, will 

 be milled to a true even surface exactly square (unless otherwise required) with the axis 

 of the main member. The minimum thickness of the end connection angles, after mil- 

 ling, shall be 1/2 inch. 



