Stainless Steel X20Cr13 +AR (Hot rolled)
Heat-treated state
EN X20Cr13 · UNS S42000
Cheapest mill condition for parts that will be fully re-heat-treated; hardness and structure vary along the bar.
Values for the +AR condition
Other X20Cr13 tempers and conditions
X20Cr13 is listed in 9 conditions; see the grade overview at X20Cr13.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Standard machining/stock condition; machine first, then harden and temper. | 420 | 700 | 22 | 200 HB | — |
Quenched and high-temperature tempered, Rm 650–850 MPa | Toughest QT class — pick when impact energy and machinability matter more than strength. | 510 | 740 | 18 | 18 HRC | — |
+ARThis page Hot rolled | Cheapest mill condition for parts that will be fully re-heat-treated; hardness and structure vary along the bar. | 520 | 820 | 15 | 24 HRC | 3.1 % IACS |
Quenched and tempered, Rm 700–850 MPa | Most common QT delivery condition for shafts, spindles and valve stems in medium sections. | 560 | 780 | 16 | 21 HRC | — |
Quenched and tempered, Rm 750–950 MPa | Intermediate strength class for pump shafts and mechanical parts in larger diameters. | 610 | 830 | 14 | 24 HRC | 3.1 % IACS |
Cold drawn | Bright, close-tolerance bar and wire for screw-machine parts and springs-in-the-hardened-state. | 640 | 820 | 12 | 24 HRC | 3.1 % IACS |
Quenched and tempered, Rm 800–950 MPa | Highest standard QT class for 1.4021 — use where yield strength dominates and impact demand is modest. | 660 | 880 | 13 | 27 HRC | — |
Hardened ~1000 °C, tempered ~350 °C | Wear-resistant condition with some residual toughness for mould inserts, shafts and pump sleeves. | 1,200 | 1,450 | 8 | 45 HRC | — |
Hardened ~1020 °C, tempered ~200 °C | Maximum hardness and edge retention for knives, surgical/dental instruments and wear plates; lowest toughness. | 1,400 | 1,720 | 4 | 51 HRC | — |
What is X20Cr13 +AR?
X20Cr13 +AR is X20Cr13 heat treated to +AR — cheapest mill condition for parts that will be fully re-heat-treated; hardness and structure vary along the bar. X20Cr13 +AR has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 79% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 215 GPa (31.2 Msi). X20Cr13 +AR 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). +A is the default condition FabDigit quotes; +AR is available on request or by drawing note.
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 — 80/100, better than 89% of stainless steel grades
- High strength — 520 MPa (75.4 ksi), better than 79% of stainless steel grades
Limitations
- Needs corrosion protection — 32/100, worse than 99% of stainless steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 91% of stainless steel grades
- Difficult to weld — 28/100, worse than 90% of stainless steel grades
- Limited ductility — 15%, worse than 89% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
X20Cr13 +AR properties
Typical room-temperature values for X20Cr13 +AR; 23 are specific to this condition. Other listed values are X20Cr13 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
X20Cr13 +AR 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
X20Cr13 +AR has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 79% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
X20Cr13 +AR is rated for continuous service to 400°C (752 °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
X20Cr13 +AR conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 99% of stainless steel grades.
Sustainability4
Producing a kilogram of X20Cr13 +AR takes about 55 MJ of energy and emits 4.6 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
X20Cr13 +AR's machinability is fair (42/100, better than 79% of stainless steel grades); weldability poor (28/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with X20Cr13 +AR
Is X20Cr13 easy to machine?
Machine in the annealed or +QT condition with sharp, positive-rake carbide, rigid setups and generous coolant; the alloy work-hardens and forms stringy chips, so finish-machine before hardening and allow ~0.05 % growth on quenching.
Can X20Cr13 be welded?
Limited weldability: preheat 200–300 °C, use 13 % Cr or austenitic 309/309L filler, keep interpass heat and temper at 700–750 °C immediately after welding to avoid hard, crack-prone martensite in the HAZ.
Can X20Cr13 be formed, bent or molded?
Cold forming only in the +A condition and with generous bend radii (≥2t); hot work 1100–850 °C followed by slow cooling and a full anneal, and never air-cool heavy sections from forging without tempering.
What surface finishes work on X20Cr13?
Passivate in nitric or citric acid after machining/grinding; the alloy takes a mirror polish best when hardened above 45 HRC, and hard chrome, nitriding or PVD (TiN/CrN) are used where extra wear or corrosion life is needed.
X20Cr13 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 for 1.4021 | 0.16 – 0.25 | 0.2 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1.5 | 0.6 |
| P | ≤ 0.04 | — |
| S≤0.030 allowed for machinability-improved variants (1.4021+S / free-cutting 1.4029) | ≤ 0.02 | — |
| Cr | 12 – 14 | 13 |
| Ninot specified in EN 10088-3; common producer/ASTM A276 residual limit | ≤ 0.75 | 0.3 |
| Fe | balance | — |
X20Cr13 +AR — frequently asked
What is X20Cr13 +AR used for?
X20Cr13 +AR is typically used for cutlery, surgical instruments, hydraulic parts and molds. In short: hardenable 13 % Cr stainless; four QT strength tempers; mould and cutlery workhorse.
What is the yield strength of X20Cr13 +AR?
X20Cr13 +AR has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 79% of stainless steel grades. Strength varies by condition: see the 9 listed tempers.
Is X20Cr13 +AR easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine in the annealed or +QT condition with sharp, positive-rake carbide, rigid setups and generous coolant; the alloy work-hardens and forms stringy chips, so finish-machine before hardening and allow ~0.05 % growth on quenching.
Can X20Cr13 +AR be welded?
Not readily — weldability is rated poor (28/100). Limited weldability: preheat 200–300 °C, use 13 % Cr or austenitic 309/309L filler, keep interpass heat and temper at 700–750 °C immediately after welding to avoid hard, crack-prone martensite in the HAZ.
What surface finishes work on X20Cr13 +AR?
Passivate in nitric or citric acid after machining/grinding; the alloy takes a mirror polish best when hardened above 45 HRC, and hard chrome, nitriding or PVD (TiN/CrN) are used where extra wear or corrosion life is needed.
Can X20Cr13 +AR be formed, bent or molded?
Cold forming only in the +A condition and with generous bend radii (≥2t); hot work 1100–850 °C followed by slow cooling and a full anneal, and never air-cool heavy sections from forging without tempering.
What is the maximum service temperature of X20Cr13 +AR?
X20Cr13 +AR is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10088-3 Stainless steels – Semi-finished products, bars, rods, wire (1.4021) — CEN (2014)
- EN 10088-1 Stainless steels – List of stainless steels (physical properties) — CEN (2014)
- ASTM A276/A276M Stainless Steel Bars and Shapes (Type 420) — ASTM International (2017)
- GB/T 1220 (2Cr13 / 20Cr13) — SAC (2007)
- 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 1.4021 / 420 bar and mould-steel datasheets — Outokumpu / Böhler / Sandvik (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.