SUS 420J1 vs SUS420J2 stainless steel: the key difference?
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SUS 420J1 and SUS 420J2 are both martensitic stainless steels under the Japanese JIS standard. They are widely used for applications requiring good hardness, moderate corrosion resistance, and high wear resistance.
Is SUS 420J2 better than 420J1?
It depends on your needs. SUS 420J2 offers higher hardness and edge retention, while SUS 420J1 offers better toughness and machinability.
Difference between 420J1 and 420J2 stainless steel?
Stainless Steel 420 / 420J1 / 420J2 Sheets & Plates Equivalent Grades:
| STANDARD | JIS | WERKSTOFF NR. | BS | AFNOR | SIS | UNS | AISI |
| SS 420 | SUS 420 | 1.4021 | 420S29 | - | 2303 | S42000 | 420 |
| SS 420J1 | SUS 420J1 | 1.4021 | 420S29 | Z20C13 | 2303 | S42010 | 420L |
| SS 420J2 | SUS 420J2 | 1.4028 | 420S37 | Z20C13 | 2304 | S42010 | 420M |
SS420 vsSUS 420J1 vs SUS420J2 stainless steel Chemical composition：
| Grade | C | Mn | Si | P | S | Cr | Ni | Mo |
| SUS 420 | 0.15 max | 1.0 max | 1.0 max | 0.040 max | 0.030 max | 12.0-14.0 | - | - |
| SUS 420J1 | 0.16-0.25 | 1.0 max | 1.0 max | 0.040 max | 0.030 max | 12.0-14.0 | - | - |
| SUS 420J2 | 0.26-0.40 | 1.0 max | 1.0 max | 0.040 max | 0.030 max | 12.0-14.0 | - | - |
SUS 420J1 vs SUS420J2 stainless steel Physical properties
| Performance Category | parameter | SUS420J1 | SUS420J2 |
|---|---|---|---|
| Physical properties | (Density) | 7.75 g/cm³ | 7.75-7.76 g/cm³ |
| (Elastic Modulus) | 200-210 GPa | 219 GPa (approx.) | |
| (Thermal Conductivity) | 25-30 W/(m·K) | 25.1 W/(m·K) at 100℃ | |
| (Thermal Expansion Coefficient) | ~11-12 × 10⁻⁶/K | 10.5 × 10⁻⁶/K (0~100℃) | |
| Mechanical properties | (Yield Strength) | ≥225 N/mm² | |
| (Tensile Strength) | ≥440 N/mm² | ||
| (Reduction of Area) | ≥50% | ||
| (Hardness) | HRC 50-55 | ||
| (Elongation) | ≥12% / ≥50% |
SUS 420J1 vs SUS420J2 stainless steel ：Heat treatment
SUS420J1 stainless steel: annealing treatment is about 750℃ fast cooling or 800℃~900℃ slow cooling
SUS420J2 stainless steel: annealing treatment is about 750℃ fast cooling or 800℃~900℃ slow cooling; quenching is 980℃~1040℃ fast cooling; tempering is 150℃~400℃ air cooling.
SUS 420J1 vs SUS420J2 stainless steel ：Uses
SUS420J1 stainless steel: high hardness and good corrosion resistance in quenched state. Used for turbine blades.
SUS420J2 stainless steel: higher hardness than SUS420J1 (20Cr13) stainless steel after quenching, used for cutting tools, nozzles, valve seats, valves, etc.
Why Choose Gnee for 420J1 / 420J2 Stainless Steel?
Gnee supplies both SUS 420J1 and SUS 420J2 in sheet, strip, bar, and machined blanks, with tailored heat treatment conditions and full mill certification.
✅ Custom tempering (QT700–QT850)
✅ Tightly controlled carbon content for stable hardening
✅ Cold rolled precision strip for razor or blade applications
✅ Full EN 10204 3.1 MTCs, hardness, and dimensional reports
We offer expert material guidance, fast delivery, and custom cutting based on your specifications.
Contact Gnee to request a quote for SUS 420J1 or 420J2 stainless steel!
