These high tensile fasteners have square head, square head with taper, hexagon with collar head, castle heads etc.  Further shapes can also be made. 

• Sizes range from 16 mm to 40mm and lengths from 30 mm to 600 mm. 
• Properties varying from 40 kg/mm2 to 120 kg/mm2; 
• Surface finishes with Rust Preventive oil coating, Hot Phosphate coating, Electro-plating finishes.
  

These drain plugs are made of low carbon and carbon steel.  They come with Hexagonal head or socket or Square head or socket.  They can be fitted with rubber 'O' ring and magnetic inserts and supplied.