The maximum effective slenderness ratio for the compression flange of a steel beam against lateral torsional buckling as per IS 800-2007 is:
The maximum slenderness ratio of the compression flange that is, the ratio of the effective length to the appropriate radius of gyration should not exceed 300 as in the case of column members.
Maximum slenderness ratios for compression members as per clause number 3.8 of IS 800:2007
Type of Member
A tension member in which a reversal of direct stress occurs due to loads other than wind or seismic forces.
A member carrying compressive loads resulting from dead loads and imposed loads.
A member subjected to compressive forces resulting only from combination with wind/earthquake actions, provided the deformation of such members does not adversely affect the stress in any part of the structure.
Compression flange of a beam restrained against lateral-torsional buckling.
A member normally acting as a tie in a roof truss or a bracing system not considered effective when subjected to a possible reversal of stresses resulting from the action of wind or earthquake forces.