SECTION B - Derry City Council

The steel sections used in the structure shall be in accordance with
the requirements of the following British Standard Specifications:-
BS 4 Part 1:2005 "Hot rolled steel sections".
BS EN 10210-2:1997 "Hot rolled structural
hollow sections".
BS EN 10056-1:1999 "Hot rolled equal and unequal
angles".
BS EN 10162:2003 "Cold formed steel sections" made from
galvanised steel sheet to BS EN
10143, with a minimum yield
strength of 280 N/mm 2 .
13 FABRICATION
The steelwork generally shall be fabricated in accordance with the
requirements of BS 5950 : Part 2 unless otherwise specified.
The ends of all sections unless specified otherwise on the contract
drawings shall be accurately sawn, square to the axis of the
member, and all burrs removed. Where loads are required to be
transmitted by direct bearing, as in stanchion shafts with slab
bases, the matching steel faces shall be machined "dead square"
and the faces protected with grease during fabrication.
Generally all bolts and nuts shall be I.S.O. metric black hexagon
and conform to the requirements of BS 4190:2001. Higher grade
bolts and nuts, except friction grip bolts, shall be ISO metric
precision bolts and nuts in accordance with the requirements of BS
3692:2001.
All threads shall be clean and the nuts shall closely fit the bolts so
that they can only just be turned by hand. Bolts shall be fitted in the
fabrications with flat washers under all nuts. Tapered washers shall
be used on tapering sections and flanges to ensure true bearing of
the bolt head or nut. Two clear threads shall show beyond the nut
on a fully tightened bolt.
The faying surfaces of HSFG bolted joints in steel 25 mm thick or
more should be checked for deformities such as bowing, twist or
rippling which would reduce the safe load capacity of the joint.
Zinc or Cadmium plated bolts, nuts and washers shall be used in
the assembly of all steelwork which has been galvanised or treated
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