This Standard applies to composite station post insulators consisting of a load bearing cylindrical insulating solid core made of resin impregnated fibres, a housing (outside the insulating solid core) made of elastomer materials (e.g. silicone or ethylene-propylene) and end fittings attached to the insulating core. Compisite station post insulators covered by this standard are subjected to cantilever, torsion, tension and compression loads. They are intended for substations with a.c. voltages greateder than 1000 V up to 245kV.