The invention provides a steel sheet for hard tinplate and a TFS steel
sheet each having an excellent formability and a temper grade of T4 to
DR9, and an efficient manufacturing method capable of selectively
manufacturing these steel sheets by using raw materials having the same
composition, wherein, the steel sheet for hard tinplate and a TFS steel
sheet having a temper grade of T4 to DR9 is manufactured from raw
materials having the same composition by changing a reduction ratio of
temper rolling or double reduce rolling for ultra-low carbon aluminum
killed steel C and P contents of which are so regulated as to satisfy a
specific formula <1>:
1.6.times.C.times.10.sup.4+0.93.times.P.times.10.sup.3.gtoreq.70 . . .
<1>.