special type for electric assembly, for sheet steel up to 4 mm thickness, for amoured conduit thread sizes, Art.-Nr.: 231320, PG: 7 - 9 - 11 - 13,5 - 16 - 21 - 29, Ø: 7 - 33 - 40; Art.-Nr.: 231322, PG: 7 - 9 - 11 - 13,5 - 16 - 21, Ø: 7 - 30