This International Standard applies to screw-type and screwless-type clamping units of any material for connecting devices, either as separate entities or as integral parts of products, for the connection of unprepared electrical aluminium (bare or plated) and copper-clad aluminium conductors (complying with IEC 228), rigid (solid and stranded), having a cross-sectional area of 2,5 mm2 up to and including 50 mm2, and equivalent AWG conductors,with a rated voltage not exceeding 1 000 V a.c. up to and including 1 000 Hz, and 1 500 V d.c. This standard also applies to aluminium bodied clamping units for the connection of rigid (solid and stranded) and flexible copper conductors (complying with IEC 228), 0,5 mm 2 up to and including 35 mm2 and equivalent AWG conductors. It contains the minimum requirements applicable to clamping units primarily suitable for connecting conductors. This standard does not apply to clamping units: a) for connection by crimping, brazing, soldering or welding; b) for data and signalling circuits; c) for flat quick-connect terminations, insulation piercing-type connections or twist-on connecting devices, for which separate pa rts exist or are under consideration. NOTES 1 In the USA and Canada, subclause 5.5.2 covering treatment of the specimens and conductors to be tested is not acceptable. 2 Flexible aluminium conductors are not covered by this standard. Upon the development of such conductors their inclusion will be considered.