Size of the type of Torx key
        
                                
        
                                
        Torx screw Torx key size
        
M2                 T6 
        
M2.5               T8
        
M3                 T10
        
M4                 T20
        
M5                 T25
        
M6                 T30
        
M8                 T45
        
M10                T50
        
M12                T55
        
M14                T55
        
M16                T60 
        
M20                T80