Stainless Steel 1.4021
EN 1.4021 · UNS S42000 · AISI/SAE 420 · JIS SUS420J1 · GB 20Cr13, 2Cr13
1.4021 (X20Cr13, AISI 420) is a medium-carbon 13% Cr martensitic stainless that hardens to about 45–50 HRC, balancing corrosion resistance with wear-resistant strength.
Reference datasheet — 1.4021 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +QT700 condition
1.4021 tempers and conditions
1.4021 is supplied in 8 conditions, soft to hard. +QT700 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for machining, cold forming or blanking before the part is hardened. | 370 | 640 | 24 | 195 HB | — |
Hot rolled | Mill hot-rolled bar for re-forging or for parts that will be fully heat treated afterwards. | 480 | 760 | 16 | 22 HRC | 3.1 % IACS |
Quenched and tempered, Rm 650–850 MPa | Highest-temper Q&T class: pick when toughness and machinability matter more than strength. | 520 | 730 | 19 | 18 HRC | — |
+QT700Default Quenched and tempered, Rm 700–850 MPa | Most widely stocked Q&T bar class — balanced strength, toughness and machinability for shafts, valve stems and fasteners. | 580 | 780 | 17 | 22 HRC | — |
Quenched and tempered, Rm 750–950 MPa | Higher-strength Q&T class for pump shafts and highly loaded bolts where some ductility is still required. | 630 | 840 | 15 | 25 HRC | — |
Cold drawn | Bright, close-tolerance bar for automatic-lathe parts and shafts that stay unhardened. | 640 | 780 | 12 | 24 HRC | 3.1 % IACS |
Quenched and tempered, Rm 800–950 MPa | Strongest standard Q&T bar class of 1.4021 — for highly stressed shafts and wear parts with reduced impact demands. | 680 | 880 | 14 | 28 HRC | — |
Hardened 980–1050 °C and low-temperature tempered | Full-hardness condition for blades, cutting tools, wear plates and plastic-mould inserts; lowest toughness. | 1,350 | 1,600 | 6 | 48 HRC | — |
What is 1.4021?
1.4021 (X20Cr13, AISI 420) is a medium-carbon 13% Cr martensitic stainless that hardens to about 45–50 HRC, balancing corrosion resistance with wear-resistant strength. It is supplied as bar, plate, strip and forgings in +A, +AR, +C and tempers from +QT650 to +QT800; the default condition gives roughly 580 MPa yield, 780 MPa tensile, 17% elongation and 235 HB (22 HRC). Service is limited to 450 °C, formability is low (score 20) and welding requires preheat with post-weld temper. Use 1.4006 where weldability matters more than hardness, or 1.4028/1.4031 for higher edge hardness. 1.4021 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,450°C (2,642 °F). 1.4021 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 215 GPa (31.2 Msi).
What is 1.4021 used for?
- cutlery
- surgical instruments
- valve trim
- molds
- pump shafts
Advantages
- Conducts heat well — 30 W/m·K (17.3 BTU/hr·ft·°F), better than 99% of stainless steel grades
- High electrical conductivity — 3.1 % IACS, better than 99% of stainless steel grades
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
- High strength — 580 MPa (84.1 ksi), better than 86% of stainless steel grades
Limitations
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 91% of stainless steel grades
- Difficult to weld — 30/100, worse than 88% of stainless steel grades
- Limited ductility — 17%, worse than 86% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
1.4021 properties
Typical room-temperature values for 1.4021-+QT700; bars are the position among stainless steel grades.
Physical3
1.4021 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
1.4021 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
1.4021 is rated for continuous service to 450°C (842 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), better than 99% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4021 conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4021 takes about 53 MJ of energy and emits 4.3 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
1.4021's machinability is fair (40/100, better than 72% of stainless steel grades); weldability poor (30/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 1.4021 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4021
Is 1.4021 easy to machine?
Machine in the annealed or ≤ 250 HB Q&T condition with sharp, rigid tooling, ~25–35 % lower speed than 304 and generous coolant; above 40 HRC switch to ceramic/CBN or grinding.
Can 1.4021 be welded?
Weldable only with preheat 200–300 °C, matching 410/420 or austenitic 309L filler, and immediate 700–750 °C temper — otherwise hard, crack-prone HAZ martensite.
Can 1.4021 be formed, bent or molded?
Cold bending and light forming only in the +A condition with generous radii (≥2t); hot work at 1100–1150 °C, stop above 900 °C, then slow-cool or anneal to avoid quench cracking.
1.4021 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CEN 10088-3 X20Cr13 | 0.16 – 0.25 | 0.2 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1.5 | 0.5 |
| P | ≤ 0.04 | |
| S≤0.015 for improved polishability grades; free-machining variant 1.4029 has 0.15–0.35 S | ≤ 0.03 | |
| Cr | 12 – 14 | 13 |
| NiNot limited by EN 10088-3; ASTM A276 Type 420 and many mill specs cap at ~0.75 | ≤ 0.75 | 0.3 |
| Fe | balance |
What surface finishes work on 1.4021?
Takes a mirror or blade polish very well; passivate per ASTM A967 (nitric or citric, avoid over-pickling) after machining, and hard chrome, nitride or PVD coat where extra wear/corrosion life is needed.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 1.4021 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does 1.4021 cost?
1.4021 is a standard-cost stainless steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1.4021 — frequently asked
What is 1.4021 used for?
1.4021 is typically used for cutlery, surgical instruments, valve trim, molds and pump shafts. In short: hardens to 45–50 HRC; workhorse 420 bar grade; stronger than 1.4006.
What is the yield strength of 1.4021?
1.4021 has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 86% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is 1.4021 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Machine in the annealed or ≤ 250 HB Q&T condition with sharp, rigid tooling, ~25–35 % lower speed than 304 and generous coolant; above 40 HRC switch to ceramic/CBN or grinding.
Can 1.4021 be welded?
Not readily — weldability is rated poor (30/100). Weldable only with preheat 200–300 °C, matching 410/420 or austenitic 309L filler, and immediate 700–750 °C temper — otherwise hard, crack-prone HAZ martensite.
What surface finishes work on 1.4021?
Takes a mirror or blade polish very well; passivate per ASTM A967 (nitric or citric, avoid over-pickling) after machining, and hard chrome, nitride or PVD coat where extra wear/corrosion life is needed.
Can 1.4021 be formed, bent or molded?
Cold bending and light forming only in the +A condition with generous radii (≥2t); hot work at 1100–1150 °C, stop above 900 °C, then slow-cool or anneal to avoid quench cracking.
What is the maximum service temperature of 1.4021?
1.4021 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 1.4021 cost?
1.4021 is a standard-cost stainless steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10088-1 Stainless steels — List of stainless steels — CEN (2014)
- EN 10088-3 Stainless steels — Semi-finished products, bars, rods, wire, sections and bright products — CEN (2014)
- ASTM A276/A276M Stainless Steel Bars and Shapes (Type 420 / UNS S42000) — ASTM International (2017)
- GB/T 1220 (20Cr13) — SAC (2007)
- JIS G4303 Stainless steel bars (SUS420J1) — JSA (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook — Stainless Steels — ASM International (1994)
- Martensitic stainless bar datasheets (1.4021 / 420) — Outokumpu / Sandvik / Böhler-Uddeholm (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.