59Si7 is a special steel. It is directly hardenable. Silicon alloy steels with medium hardenability. 59Si7 is used in springs for heavy duty service and is available as hot worked and cold finished bar, rod, and wire; seamless mechanical tubing; bar subject to end-quench hardenability requirements


%C %Si %Mn %P %S Cr Mo Ni other
0.55-0.63 1.6-2 0.6-1 Max0.03 Max0.03


Hot working:

Forging temperature range: 1200-850℃

Note: Heat to 1200 ℃. Do not forge below 850.

Heat treatment:

annealing ℃ Normalizing ℃ Hardening temperature ℃
700-760 900 850-880


Main application:

heavy-duty springs, coil springs.

Shape of product:

round, other shape depend on customer needs