Structural Steel Work

The checks to be observed during supervision of structural steel  work are : 

1. Ensure that all  steel brought to site is of specified category, grade and quality and where welding is specified, it is of the  appropriate grade. 
2. Check that weights and dimensions are correct. 
3. Check that first coat of protective paint has been applied where specified. Take particular care of portions which will not be accessible after fitting hoisting. 
4. See that contractor has proper tools for drilling, shearing, sawing, gas  cutting, welding, grinding and riveting. 
5. See that all the  material is free from bends, twists  and  waviness. Where necessary, get it  straightened or flattened by pressure. 
6. Cutting  should be effected by shearing, sawing or  gas cutting. Protrusions if any, should be rectified by grinding edges. 
7. Holes should be drilled and not punched. Before drilling, ensure that all the members are clamped. If this is not practicable, prepare a template so that the position of the holes is correctly marked. Before rivettingholting, make sure that the holes are concentric. 
8. The hole shall be 1.5 mm larger  in  case of the diameter of the rivetholt being 25 mm or less and 2 mm larger in case of the  diameter of the rivetholt exceeding 25 mm. 
9. The component parts shall be assembled in  such a way that they are neither twisted nor damaged in handling.
10. Rivets shall be of proper qudity and shall be heated  uniformly without burning or excessive scaling. 
11. See that rivet heads are neatly finished. For multiple rivetted section, service bolts should be provided in every third or fourth hole. 
12. The threaded portion of each bolt  should project through the nut at least two threads. 
13. See that washers are provided  on bolt  heads and nuts. 
14. See that heel plates of trusses are slotted at one end to allow for expansion where specified and that dimensions of steel trusses are correct. 
15. Where Welding is  specified, study the  Indian standard Codes on the subjat for achieving best workmanship. 
16. In  steel fabrication, mistakes once made cannot be rectified easily. Hence great care must be taken that  due allowance has been made in the components of particularly large  span framed graders while fabricating on ground, so that the deflection due to dead weight does not create any problem  while fixing such girders on supports.