Chemical Composition HTB-1 Standard: BS 1400 Copper AlloysCUSNPBZNFENIALMNSIImpurities HTB 1 55 Min 1 0.5 Rem. 0.7 - 2 1 0.5-2.5 0.1-3 0.1 0.2 HTB-2 Standard: 304-1981 Copper AlloysCUSNPBZNFEALMNSIImpurities HTB-2 55 Min 0.2 0.2 Rem. 1.5-3.25 3-6 4 0.1 0.2 HTB-3 Standard: BS 1400 Copper AlloysCUSNPBZNFENIALMNSIImpurities HTB-3 55 Min 0.2 0.2 Rem. 1.5-3.25 1 3-6 1.5-4 0.1 0.2 Physical Properties Manganese Bronze Grade B.S. 1400: 1985Nominal Composition2% PS N/mm MinTensile Strength N/mm MinElongation % MinBrinell Hardness Min HTB1 58/1/1/1/39 170 450 20 110 HTB1 58/1/2/3/36 HTB1 58/2/2/4/34 450 750 8 180 HSBC4 410 755 12 200 HSBC3 305 635 15 165