SCR420H Structual Steel Bar


JIS SCR420 alloy Steel is a high quality Quenched and Tempered Alloy Structural steel, It belong to the high quality low carbon,Low alloy chromium, molybdenum, nickel case hardening steel. Oil Quenched & Tempered Hardness is 28-34 HRC. JIS SCR420 steel Annealing delivery hardenss less than 250HB. SCR420 with a lower carbon content range, So JIS SCr420 alloy steel have good weldability.


Chemical Composition:

0.17~0.230.15 ~ 0.350.55 ~ 0.90≤0.030≤0.0300.85~1.25≤0.30


Mechanical Propoerties:

Yield Strength
Tensile Strength
Elongation δ5 (%): Reduction
of area ψ (%):
Impact energy
Akv (J):
Impact toughness
value αkv (J/cm2)
≥ 835(80) ≥ 895(85) ≥ 11≥ 45≥ 41≥ 39(4)≥ 245 HB



Heat treatment:

  • Annealing of SCR420 Alloy structural steel

Slowly heated to 850 ℃ and allow enough times, let the steel to be thoroughly heated, Then cool slowly in the furnace. The SCR420 alloy steel will get MAX 250 HB (Brinell hardness).

  • Hardening of JIS Alloy structural steel SCR420

First quenching heated slowly to 880°C, Then after adequate soaking at this temperature quench in oil or water. Temper as soon as tools reach room temperature. Second quenching heat to 780-820°C, then quenching in oil or water.

  • Tempering of SCR420 Alloy structural steel

Heat to 20°C, then cool in water or oil.normal delivery hardness 179HB Min.


Delivery Status: 


Delivery in rolled or forged condition. According to the demand side can also heat treatment (normalizing, annealing or high temperature tempering) state delivery. Delivery status should be indicated in the contract.

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