National structural steelwork specification for building construction download

Login to CIS. Back to publisher list. The Construction Information Service brings together a comprehensive collection of essential technical documents from a wide range of publishers in one online package. Covering all aspects of building, engineering, design and construction, it provides its users with a single source for all their technical information needs.

Contact us today to find out how to become a subscriber to this indispensable service. British Constructional Steelwork Association , Document Status Withdrawn, Document not available for download Supplement Core Supplement Series Publication Abstract The National structural steelwork specification NSSS enables design and execution of structural steelwork to British and adopted European Standards, covering information required and provided by the steelwork contractor, materials, workmanship, protective treatments and quality management.

History Superseded by the 7th edition, , from 1st January Information NBS NBS has produced specification systems and information products for construction industry professionals for more than 40 years. Superseded by the 7th edition, , from 1st January First edition: March Second edition: October Third edition: July , second impression March Fourth edition: May Fifth edition: January CE Marking version: October Erection Drawings : Drawings, prepared if necessary by the Steelwork Contractor, showing details to amplify the information given in the Steelwork Contractor's erection method statement and showing details of any temporary steelwork see 8.

Note: These responsibilities are distinct from those of the Inspection Authority if appointed. Fabrication Drawings : Drawings or electronic equivalent prepared by the Steelwork Contractor, showing all necessary information required to fabricate the structural steelwork. Fittings : Plates, flats or rolled sections which are welded or bolted to structural steel components.

Foundation Plan Drawings : Drawings, prepared by the Steelwork Contractor or the Engineer, indicating location of column bases and details of foundation connections to the steelwork. General Arrangement Drawings : Drawings, prepared by the Steelwork Contractor, showing plans, cross sections and elevations, main dimensions and the erection marks of components.

Inspection Authority : A competent independent person or organisation which verifies compliance with this Specification and the Project Specification. Ordinary Bolt Assemblies : A bolt used in a non-preloaded bolt assembly which is designed to carry forces in shear and bearing or tension.

Production Test Plate : A plate used for testing purposes, which is made of the same material and using the same procedures as the joint in a component. Programme : The programme of dates given in the Project Specification, or agreed with the Steelwork Contractor, for: the release of all necessary information for the progress of The Works; the preparation, submission and acceptance of fabrication drawings, calculations and information; the intended starting and completion dates for steelwork erection.

Project Specification : A specification prepared for a specific building project see "The Works" which includes the latest version of the National Structural Steelwork Specification and qualifies it where necessary. Quality Assurance : Activities concerned with the provision of systems, equipment and personnel necessary to achieve the required level of quality.

Stiffener : A steel component, generally a plate, in a connection or attached to a member to increase the strength of a panel zone within the joint or member. If required by the Project Specification, the Steelwork Contractor may also be responsible for design. Works, the : Those parts of the construction works described in the Project Specification as structural steelwork.

Fillet Weld : A weld, other than a butt or edge weld, which is approximately triangular in transverse cross section and which is made without preparation of the parent material.

Full Penetration Weld : A weld between elements which may be in-line, in the form of a tee, or a corner in which the weld metal achieves full penetration throughout the joint thickness. Partial Penetration Weld : A weld formed using a technique which ensures a specified penetration which is less than the depth of the joint and hence intentionally not full penetration.

Full Strength Weld : Any of the above welds designed to develop the full strength of the parts which it connects. The non-exhaustive checklists given in Tables 1. TABLE 1. Information required by the Steelwork Contractor i A statement describing the design concept.

If connection design is to be in accordance with BS or BS EN , the forces and moments should be the factored values as defined by the code.

Appropriate amendments to this Specification should be included since these factors are outside the intended scope.

Note: The role of the Engineer will need to be clarified under this option, and terms may need to be redefined. Information required by the Steelwork Contractor i A statement describing the design requirements. Note: Routine welding procedure requirements are in 5. Information required by the Steelwork Contractor i A Site plan showing position of datum level and setting-out lines. Information required by the Steelwork Contractor i The date s of issue of the Design Drawings or data for construction and other information necessary for the progress of the Works.

Only products with a CE mark shall be used if a harmonised standard exists for that constituent product type. Note: This only refers to standards harmonised under the Construction Products Directive. Note: When specifying and ordering, the full steel designation should be given including the standard number, strength grade and impact quality e.

BS EN SJ0 so that the correct properties for fracture toughness and weldability are ensured. When ordering, consideration should also be given to specifying particular options available in the steel product standards e. Note: This requirement is necessary to ensure that the weldability of the steel in terms of its CEV matches that required for the welding procedure specification, and it supersedes the testing requirements specified in BS EN which permits steel products of qualities SJR, SJ0, SJR or SJ0 to be supplied with non-specific test reports.

The Steelwork Contractor shall have access to inspection documents to BS EN provided by manufacturers of all steel products used in the Works. If requested, the Steelwork Contractor shall make these inspection documents available to the Engineer or Inspection Authority. Any further tests to establish whether the mechanical properties of steel products are appropriate for use in the Works shall be undertaken by a laboratory certified as competent to BS EN ISO IEC TABLE 2.

Surface defects in hot rolled sections, plates and wide flats revealed during surface preparation which are not in accordance with the requirements of BS EN shall be rectified accordingly. Surface defects in hot rolled hollow sections revealed during surface preparation which are not in accordance with the requirements of BS EN shall be rectified accordingly.

Surface defects in cold formed hollow sections revealed during surface preparation which are not in accordance with the requirements of BS EN shall be rectified accordingly. Consumables used for completing welding of steels to BS EN shall have a weather resistance at least equivalent to the parent metal. Any drying or baking of consumables before issue shall be carried out in accordance with the manufacturer's recommendations. Fasteners supplied as proprietary items see 2.

Special fasteners shall only be used if the manufacturer publishes suitable product information in the form of a component specification and provides a certificate of conformity that the fasteners have been supplied in accordance with the component specification.

If provided, the Steelwork Contractor shall make certificates of conformity provided by manufacturers of structural fasteners available to the Engineer or Inspection Authority, if requested. The preloaded bolt assemblies in Table 2. Preloaded HV assemblies to BS EN or -8 may only be used if the Project Specification permits this and provides a complete specification for their use.

Note: It is recommended that assemblies from only one of the two different systems are used exclusively on an individual project. Bolts and nuts from the two different systems HR and HV shall not be mixed. See clause 3.

Note: For coatings for bolt assemblies see 2. Note: These limits are to reduce the risk of occurrence of liquid metal assisted cracking.

The galvanizer should measure and record the composition of the zinc in the bath. Note: Proprietary items include threaded tie bars, connectors, couplers and turnbuckles. Note: The availability of information on constituent products that have the required CE marking see 2. The system shall have means of identifying that the latest information provided by the Engineer is being used and that superseded information has been withdrawn.

The system shall be open to audit. Components which are identical in all respects may have the same erection mark. Preferred scales are or larger. The drawings shall identify each component with respect to its component specification, its location relative to other components and the grid. Details at an enlarged scale should also be made if these are necessary to show the assembly of components.

Similar information shall also be provided for components connecting to walls and other concrete surfaces see Table 1. Complete details of fixing steel and bolts to the foundations or walls, method of adjustment and packing space shall be provided.

Such details shall be available to the Employer if so specified in the Project Specification or on request. The system shall include all necessary information and technical requirements for the manufacture of each component together with full details of the date when component information is released for manufacture.

The component specification shall specify the dimensions and quality of constituent products and the surface treatment.

A reference system to connection types may be utilised. Unless specified otherwise by the Project Specification, such holes and fittings may remain on the permanent structure. Account shall be taken of 5. Welding inspection requirements which differ from those specified in 5.

Note: The programme should allow for a review of the computer model to be made in advance of the review of any calculations and any associated sketches and drawings.

The Steelwork Contractor shall mark references on the General Arrangement drawings or provide another suitable system such that a connection calculation or standard simple connection can be identified to a specific location on the structure. Calculations shall include sketches or drawings showing the arrangement of the connection and shall be referenced to a location on the structure. If necessary drawings showing complex geometry shall also be submitted.

Note: If industry standard connections are used, only a reference to the standard connection need be submitted. Acceptance does not relieve the Steelwork Contractor of the responsibility for accuracy of the calculations, detail dimensions on the drawings, nor the general fit-up of parts to be assembled on site 3.

Information submitted must be B "Accepted subject to comments" amended in line with the comments, but need not be re-submitted. Information must be amended in C "Not Accepted" the way indicated and re-submitted for acceptance. Unless required by the Project Specification individual pieces do not need to be traceable to a particular inspection document. Completed components shall be marked with a durable and distinguishing erection mark in such a way as not to damage the material.

Hard stamping may be used for steel grades up to and including S, except where otherwise specified in the Project Specification. Where areas of steelwork are indicated on the drawings, or fabrication information, as being unmarked, they shall be left free of all markings and hard stamping. Particular care shall be taken to stiffen free ends and adequately protect any machined surfaces. Hand-held cutting shall only be used if it is impractical to use machine thermal cutting.

Any areas where thermal cutting is not permitted shall be so indicated in the Project Specification see Table 1. Note: Thermal cutting refers to plasma cutting, laser cutting or flame cutting. Thermally-cut re-entrant corners and notches e. Prior to galvanizing these locations shall be specifically inspected to verify conformity. Columns and compression members intended to be in direct bearing shall be fabricated to the accuracy given in 7.

The butting surfaces of column sections which are one metre and over in width or depth and are to be in direct bearing shall be specially prepared so that after erection both the deviation in plumb in 9. Holes shall be dressed as required to remove burrs and protruding edges. Note: The Project Specification should indicate any areas on components where due to design requirements thermal cutting or full size hole punching is not permitted see Table 1.

The capability of holing processes shall be checked periodically in accordance with BS EN It is recommended that the checking of process equipment capability is undertaken in liaison with the equipment manufacturer or supplier. Drifts may be used but holes shall not be distorted. The parts shall be separated after drilling and any burrs removed. Any areas on components where holes are not to be punched full size shall be indicated in the Project Specification see Table 1.

Drifting of holes to align the components shall be permitted, but must not cause damage or distortion to the final assembly see 6. After curving or straightening, welds within the area of curving or straightening shall be visually inspected.

Welds which are to be subject to non-destructive testing shall have these tests carried out after curving or straightening. They shall be kept clean and supported in such a manner as to avoid permanent distortion. All welding documentation welder qualifications, welding procedure qualification records, welding procedure qualifications and associated work instructions shall be reviewed for applicability by the person responsible for welding coordination.

If requested, the documentation shall be made available to the Inspection Authority if appointed. The Steelwork Contractor shall ensure that constituent product materials to be welded are compatible with the welding procedure being used. Precautions shall be taken to ensure cleanliness of the connection prior to welding.

The certification shall remain valid providing it complies with the conditions for re- approval of certification specified in BS EN If welding is to be undertaken on coated steel, the WPQR shall be qualified on the maximum nominal thickness of coating. Note: This requirement may only be applied to qualification of procedures for fillet welds of leg length not above 12mm joining S material with thickness not above 17mm.

They shall be provided for the welder prior to the commencement of the Works and shall be suitable for the joint configuration and material to be welded.