The invention comprises azo dyestuffs which are obtained when diacylmethanes of the formula R-CH2-R1 wherein R represents an acyl radical of an aliphatic, cyclo-aliphatic or aromatic monocarboxylic acid and R1 represents an acyl radical of an aliphatic, cycloaliphatic or aromatic monocarboxylic or sulphonic acid, are coupled stepwise with diazotized amines, the acyl group R of the intermediate compound resulting after the first coupling being split off by saponification under alkaline conditions before or during the second coupling. The hydrocarbon radicals of the acyl groups may contain a substituent or substituents which are water solubilizing or do not alter the water solubility of the dyes, e.g. a sulphonamide group in which the hydrogen atoms may be replaced by hydrocarbon radicals optionally further substituted, nitro, sulphonic acid, carboxy, sulphone, alkylsulphamino or arylsulphamino groups or acetylated amino or urethane groups. The acetylated amino or urethane group can be converted by hydrolysis into an amino group and the nitro group reduced to an amino group. The same or different diazotized amine(s) may be employed in each step or 2 mols. of diacylmethane can be coupled in either order with 1 mol. of tetrazo compound and 2 mols. of a diazo compound. Preferred diazo and tetrazo compounds are those of the benzene or naphthalene series or derived from heterocyclic compounds of aromatic character. Preferably at least one of the diazo compounds contains in ortho position to the azo group a metal complex forming substituent, e.g. a hydroxyl, carboxyl, sulphonic amide or amine group or a group, e.g. alkoxy, which can be converted into such a substituent before or during a metallizing reaction. The cleavage of the acyl radicals may take place during the second coupling reaction or may be effected with alkaline agents, e.g. a basic salt, or a hydroxide of an alkali- or alkaline earth metal, ammonia, magnesium oxide, sodium bicarbonate or carbonate. Anili-oxidizing substances may be present, e.g. sodium sulphite or thiosulphate or grape sugar. Metallizable dyes may be metallized by normal methods, e.g. with solutions of salts of copper, cobalt, nickel, chromium or zinc. Preferably metal complexes of disazo dyes contain one atom of copper, nickel, cobalt or zinc and those of tetrakisazo dyes 2 atoms of those metals. Cobalt or chromium complexes may be 1 : 1 or 1 : 2 complexes. The dyes are suitable for dyeing, padding or printing or as pigments depending on whether they contain water-solubilizing groups or not. Fibres specified include those of natural and regenerated cellulose, cellulose acetate and triacetate, wool, silk, polyamide fibres of dicarboxylic acids and diamines, polymeric lactams or o -aminomonocarboxylic acids or fibres of polyterephthalic acid ethylene glycol esters. Pigments may be produced by reacting the water-soluble azo dyes or metal complexes with a barium, calcium, strontium or lead salts. In examples: acetyl-4-methylbenzenesulphonylmethane is dissolved in aqueous sodium hydroxide solution, coupled with diazotized 2-amino-benzene-1-carboxylic acid, the product is warmed with aqueous sodium hydroxide and sodium sulphite, the solution is cooled and coupled with diazotized 2-amino-1 - hydroxy - benzene - 4 - sulphamide (1); and diazotized 2 - amino - 1 - hydroxy - 4 - nitrobenzene-6-sulphonic acid is coupled with acetylnaphthalene - (2) - sulphonyl methane in aqueous sodium hydroxide solution, hydrolysis is effected by warming the intermediate with aqueous sodium hydroxide and sulphite and the mixture is cooled and coupled with diazotized 2 - amino - 1 - hydroxy - 4 - nitrobenzene (2). The dye in (2) is converted to the copper complex by heating with aqueous copper sulphate solution and sodium acetate. In Example (7), 5-acetoaminonaphthalene-(2)-sulphonyl - acetyl - methane is coupled with diazotized 2 - amino - 1 - hydroxybenzene - 4-sulphonic acid, the product is treated with sodium hydroxide and bisulphite, copper sulphate and triethanolamine is added to the reaction mixture which is then coupled with tetrazotized 4,41-diamino-diphenyl. Heterocyclic monoamines which may be used in the latter example instead of 2-amino-1-hydroxybenzene - 4 - sulphonic acid include 2 - amino-1 - hydroxy - 4 - pyrrolidonyl benzene and 2 - amino - 1 - hydroxy - 4 - oxazolidonylbenzene. Other examples and long lists of alternative starting materials are furnished. The metallization of dyes on the fibre is described.ALSO:Metallized dyeings are produced on textile fibres by normal methods using metallizable azo dyestuffs which are obtained when diacylmethanes of the formula R-CH2-R1 wherein R represents an acyl radical of an aliphatic, cycloaliphatic or aromatic monocarboxylic acid and R1 represents an acyl radical of an aliphatic, cycloaliphatic or aromatic monocarboxylic or sulphonic acid, are coupled stepwise with diazotized amines, the acyl group R of the intermediate compound resulting after the first coupling being split off by saponification under alkaline conditions before or during the second coupling. In example (A) wool is placed in a bath comprising the dye obtained by coupling diazotized 2-aminobenzene-1-carboxylic acid with acetyl-4-methylbenzene sulphonyl methane hydrolysing the product and coupling with diazotized 2-amino-1-hydroxy-benzene-4-sulphamide and ammonium sulphate, aqueous copper sulphate solution is added and the bath boiled. Corresponding dyeings are obtained using cobalt or nickel sulphate as metallizing agent.