IS 6623 : 2004 High Strength Structural Nuts - Specification

1 Scope

This standard covers the requirements of large series hexagon,high strength structural steel nuts of property classes 8 and 10 inthe size range of M 12 to M 36 suitable for use in bothfriction-type and bearing-type of structural steel connections.Nuts to this standard when matched with the appropriate bolts havebeen designed to provide an assembly with a high level of assuranceagainst failure by thread stripping on over tightening.

Note - Attention is drawn to the importance of ensuring that thenuts are correctly used, if satisfactory results are to beobtained.

2 References

IS 1367 Technical supply conditions for threaded steel fasteners:

    Part 1 : 2002 General requirements of bolts, screws, studs and nuts

    Part 2 : 2002 Tolerance for fasteners - Bolts, screws, studs and nuts - Product grades A, B
    and C

    Part 6 : 1994 Mechanical properties and test methods for nuts with specified proof loads

    Part 10 : 2002 Surface discontinuities of nuts

    Part 13 : 1983 Hot-dip galvanized coatings on threaded fasteners

    Part 17 : 1996 Inspection, sampling and acceptance procedure

    Part 18 : 1996 Packaging

IS 3757 : 1985 Specification for high strength structural bolts

IS 4218 ISO General purpose metric screw threads:

    Part 1 : 2001 Basic profile

    Part 2 : 2001 General plan

    Part 3 : 1999 Basic dimensions

    Part 4 : 2001 Selected sizes for screws, bolts and nuts

IS 6649 : 1985 Specification for hardened and tempered washers for high strength structural bolts and nuts

IS 14962 ISO general purposes metric screw threads - Tolerances:

    Part 1 : 2001 Principle and basic data

    Part 2 : 2001 Limits of sizes for general purpose external and internal screw threads -
    Medium quality

    Part 3 : 2001 Deviations for constructional screw threads

    Part 4 : 2001 Limits of sizes for hot-dip galvanized external screw threads to mate with
    internal screw threads tapped with tolerance position H or G after galvanizing

    Part 5 : 2001 Limits of sizes for internal screw threads to mate with hot-dip galvanized
    external screw threads with maximum size of tolerance position h before galvanizing