410 vs 420 Stainless Steel
Side-by-side comparison · Composition · Properties · Selection guide
Both are 12–14% chromium martensitic steels hardened by quench and temper. 410 carries up to 0.15% carbon and reaches about 38–42 HRC with good toughness; 420 starts at 0.15% carbon and reaches 48–52 HRC for real edge retention, trading away some toughness and corrosion margin.
Full datasheets:410 Stainless Steel·420 Stainless Steel
At a Glance
| 410 | 420 | |
|---|---|---|
| Type | Martensitic | Martensitic |
| UNS | S41000 | S42000 |
| Standard | ASTM A240/A240M, A276 | ASTM A240/A240M, A276 |
| Density | 7.74 g/cm³ | 7.75 g/cm³ |
Corrosion Resistance and Service Limits
410
- Corrosion resistance depends on chromium, carbon, heat-treatment condition and surface finish and is generally below common 304-type austenitic stainless steel.
- Avoid assuming hardness implies corrosion resistance. Chlorides, tempering condition, retained scale and grinding contamination must be evaluated for the part.
420
- Corrosion resistance depends on chromium, carbon, heat-treatment condition and surface finish and is generally below common 304-type austenitic stainless steel.
- Avoid assuming hardness implies corrosion resistance. Chlorides, tempering condition, retained scale and grinding contamination must be evaluated for the part.
Fabrication and Heat Treatment
| Operation | 410 | 420 |
|---|---|---|
| Welding | Welding requires grade- and section-specific preheat, filler and post-weld heat treatment to control hard cracking and restore properties. | Welding requires grade- and section-specific preheat, filler and post-weld heat treatment to control hard cracking and restore properties. |
| Forming | Carry out substantial forming in the annealed condition and allow for reduced ductility as carbon and target hardness increase. | Carry out substantial forming in the annealed condition and allow for reduced ductility as carbon and target hardness increase. |
| Machining | Machine in the annealed or softened condition where possible; hardened material needs appropriate tooling, speeds and allowance for final grinding. | Machine in the annealed or softened condition where possible; hardened material needs appropriate tooling, speeds and allowance for final grinding. |
| Heat treatment | Final properties depend on a specified austenitize, quench and temper route. Temperature, hold time, section size and required hardness belong on the order. | Final properties depend on a specified austenitize, quench and temper route. Temperature, hold time, section size and required hardness belong on the order. |
Chemical Composition (wt%)
| Element | 410 | 420 |
|---|---|---|
| C | 0.08–0.15 | ≥0.15 |
| Mn | ≤1.00 | ≤1.00 |
| Si | ≤1.00 | ≤1.00 |
| Cr | 11.5–13.5 | 12.0–14.0 |
| Ni | ≤0.75 | — |
| P | ≤0.040 | ≤0.040 |
| S | ≤0.030 | ≤0.030 |
Mechanical Properties
| Property | 410 | 420 |
|---|---|---|
| Tensile strength (annealed) | ≥450 MPa (65 ksi) | — |
| Yield strength (annealed) | ≥205 MPa (30 ksi) | — |
| Elongation (50 mm) | ≥20% | — |
| Hardness (hardened + tempered) | up to ≈40–45 HRC | 48–52 HRC (typ.) |
| Condition (as supplied) | — | Annealed |
| Hardness (annealed) | — | ≤223 HBW |
| Tensile (hardened, typ.) | — | ≈1600–1800 MPa |
Which One Should You Choose?
Choose 410 for:
- Valve trim, pump shafts and fasteners
- Steam and gas turbine components
- Parts needing impact toughness with moderate hardness
- General corrosion-plus-wear service
Choose 420 for:
- Knife blades, scissors and cutting edges
- Surgical and dental instruments
- Plastic injection mold cavities (420 mold steel)
- Wear parts polished to fine finishes
Our verdict
Pick by target hardness. Below roughly 45 HRC, 410 gives a tougher, more forgiving part; at 48 HRC and above only 420's carbon gets you there. Corrosion resistance in both depends on proper hardening and a fine surface finish — annealed or rough-ground martensitic steel stains quickly regardless of grade.
Cost and Availability
Compare the current stock position, mill route, minimum production quantity, processing yield, testing and delivered cost for 410 and 420 at quotation time. A fixed price ratio would be misleading because product form, size, condition and market timing can change the commercial result.
Do Not Substitute Without Review
Do not replace 410 with 420, or the reverse, from the grade name alone. Recheck chemistry, mechanical-property condition, product standard, dimensions, corrosion environment, welding procedure and project approval before substitution.
Frequently Asked Questions
Which is more corrosion resistant, 410 or 420?
Properly hardened and polished, 410 holds a slight edge — more of its chromium stays in solution at lower carbon. Both are indoor/mildly-wet grades; neither approaches 304 for atmospheric duty.
Can 410 and 420 be welded?
With preheat, controlled interpass and post-weld tempering, 410 is weldable and commonly repaired. 420's higher carbon makes it crack-prone and it is generally joined mechanically or by specialist procedures only.
Do 410 and 420 need heat treatment?
For useful martensitic strength and corrosion performance they are normally hardened and tempered. The chosen condition controls hardness, toughness, dimensional change and machinability.
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Technical content updated: 2026-07-29
Organizational author: Tsingshan (Shandong) Iron & Steel Co., Ltd..Review method, status and limitations.