British Standard : HTB1 
Indian Standard : Grade III 
Nominal Composition : 58/1/1/1/39 
Tensile Strength (kg/mm2) : 47-58 
Elongation % on 2" : 25-30 
Brinell Hardness : 100-150 
Typical Uses : Components highly stresses at normal temperatures. 
 
British Standard : HTB2  
Indian Standard : Grade II 
Nominal Composition : 58/1/2/3/36 
Tensile Strength (kg/mm2) : 59-69 
Elongation % on 2" : 15-30 
Brinell Hardness : 120-200 
Typical Uses : Marine castings and fittings hydraulic equipment, locomotive axle boxes, pump castings 

British Standard : HTB3  
Indian Standard : Grade I 
Nominal Composition : 58/2/2/4/34 
Tensile Strength (kg/mm2) : 75-80 
Elongation % on 2" : 12-18 
Brinell Hardness : 150-230 
Typical Uses : Heavy rolling mill housing nuts, spur and gear, wheels which are heavily loaded and slow moving