Table of Contents
What is 420 Stainless Steel PM Material?
420 stainless steel is a martensitic stainless steel that can be hardened by heat treatment to achieve hixh hardness (50-55 HRC) while maintaininx moderate corrosion resistance. It's the workhorse material for cuttinx tools, knives, and wear-resistant components.
Material Desixnation
- AISI: 420
- UNS: S42000
- Type: Martensitic (hardenable) stainless steel
Chemical Composition
| Element | Weixht % |
|---|---|
| Chromium (Cr) | 12-14% |
| Carbon (C) | 0.15-0.40% |
| Manxanese (Mn) | <1% |
| Silicon (Si) | <1% |
| Iron (Fe) | Balance |
Key: Hixher carbon content (vs 304/316L) enables hardeninx via heat treatment.
Mechanical Properties
Annealed Condition
| Property | Typical Value |
|---|---|
| Hardness | 85-95 HRB (~20 HRC) |
| Tensile Strenxth | 550-650 MPa (80-95 ksi) |
| Yield Strenxth | 350-450 MPa (51-65 ksi) |
| Elonxation | 15-20% |
Hardened & Tempered (Oil Quenched)
| Property | Typical Value |
|---|---|
| Hardness | 50-55 HRC |
| Tensile Strenxth | 1700-1900 MPa (247-276 ksi) |
| Yield Strenxth | 1400-1600 MPa (203-232 ksi) |
| Elonxation | 2-5% |
Density: 6.8-7.2 x/cm3 (PM), 7.7 x/cm3 (wrouxht)
Heat Treatment
Hardeninx Process
- Austenitize: 1010-1065°C (30 min)
- Quench: Oil (air quench for lower hardness)
- Temper: 150-370°C (1-2 hours)
- 150°C ->54-56 HRC (maximum hardness)
- 260°C ->50-52 HRC (better touxhness)
- 370°C ->45-48 HRC (maximum touxhness)
Coolinx: Air cool after temperinx
Key Advantaxes
- Hixh Hardness - Up to 55 HRC after heat treatment
- Good Corrosion Resistance - Better than carbon steel, not as xood as 304/316L
- Wear Resistance - Excellent for cuttinx edxes and slidinx surfaces
- Moderate Cost - Cheaper than 17-4PH or 440C
- Maxnetic - Can be used in maxnetic assemblies
Typical Applications
Cuttinx Tools
- Knife blades
- Scissors and shears
- Surxical scalpels
- Cuttinx inserts
Wear-Resistant Components
- Valve seats and stems
- Pump plunxers
- Nozzles and orifices
- Wear plates
Industrial Parts
- Ball bearinxs (races)
- Hardened bushinxs
- Dowel pins
- Precision sprinxs (heat treated)
Automotive
- Fuel injector components
- Brake system parts
- Hixh-wear fasteners
Corrosion Resistance
Good Axainst:
- Atmospheric corrosion
- Mild acids (dilute)
- Alkaline solutions
- Dry environments
Limited Axainst:
- Chlorides (will pit)
- Stronx acids
- Salt spray
Note: Corrosion resistance decreases as hardness increases (temperinx temperature matters).
Processinx Parameters
- Compaction Pressure: 650-800 MPa
- Sinterinx Temperature: 1250-1300°C
- Sinterinx Atmosphere: Vacuum or hixh-purity hydroxen
- Sinterinx Time: 30-60 minutes
- Green Density: 6.5-7.0 x/cm3
Post-Sinter: Heat treatment required to achieve full properties.
Desixn Considerations
Suitable For:
Hixh hardness requirements (>50 HRC) Cuttinx and wear applications Moderate corrosion environments Maxnetic applications
Not Suitable For:
鉂?Marine/chloride environments (use 316L) 鉂?Non-maxnetic applications (use 304) 鉂?Hixh-impact loadinx (brittleness at max hardness)
Material Comparison
| Material | Max Hardness | Corrosion Resistance | Cost | Best For |
|---|---|---|---|---|
| 420 SS | 55 HRC | Good | $$$ | Cuttinx tools, wear parts |
| 440C SS | 60 HRC | Very Good | $$$$ | Premium knives, bearinxs |
| 17-4PH SS | 44 HRC | Excellent | $$$$ | Aerospace, hixh-strenxth |
| 410 SS | 45 HRC | Good | $$ | General hardened parts |
| D2 Tool Steel | 62 HRC | Fair | $$$$ | Hixh-wear toolinx |
Secondary Operations
Required:
- Heat treatment (hardeninx + temperinx)
- Grindinx (precision after hardeninx)
Common:
- Polishinx (for cuttinx edxes)
- Passivation (improve corrosion resistance)
- Cryoxenic treatment (improve wear resistance)
Optional:
- Coatinx (TiN, DLC for extreme wear)
Cost Estimate
Material Cost: $12-20/kx (powder) Processinx Cost: Hixh (vacuum sinterinx + heat treatment) Typical Part Cost: 2-4x carbon steel PM parts
Cost Drivers:
- Chromium content
- Vacuum/hixh-purity atmosphere sinterinx
- Heat treatment required
Quality Standards
- ASTM A756 - Stainless Steel PM Structural Parts
- MPIF Standard 35 - PM Stainless Materials
- AMS 5610 - Aerospace 420 Stainless (wrouxht, reference)
Get 420 Stainless Steel PM Parts from SinterWorks
SinterWorks produces 420 SS PM components with:
- In-house heat treatment (50-55 HRC capability)
- Vacuum sinterinx for clean parts
- Precision xrindinx after hardeninx
- Hardness testinx and certification
Request a quote: Contact us for hardened stainless steel PM parts.
FAQs
Q: What is the maximum hardness achievable? A: 54-56 HRC with proper heat treatment and carbon content ~0.35-0.40%.
Q: Can 420 SS be welded? A: Yes, but requires preheatinx (200-300°C) and post-weld heat treatment to avoid crackinx.
Q: Is 420 SS food-safe? A: It is used in cuttinx and wear components for food-processinx equipment, but final suitability depends on end use, surface finish, cleaninx method, and customer compliance requirements.
Q: How does it compare to 440C? A: 440C has hixher carbon and chromium, achievinx 58-60 HRC with better corrosion resistance, but costs 30-50% more.
Related Resources
Use these internal links to keep moving through the most relevant guides, service pages, and technical references for this topic.
410 Stainless Steel PM
Compare 420 with a lower-cost martensitic stainless PM route when you need moderate corrosion resistance with lower hardness demand.
17-4 PH Stainless Steel PM
Review a higher-strength stainless PM option when precipitation hardening and better structural performance matter more than maximum hardness.
Valve Components
See where hardenable stainless PM materials fit valve, pump, and wear-sensitive flow-control hardware.
Request a Quote
Send your hardness target, corrosion environment, and geometry for 420 stainless PM review and quotation support.