Stainless Steel 4Cr13-QT300
Heat-treated state
EN 4Cr13 · UNS S42000
QT300 = q&T 300 °C
Slightly tougher mould / valve-trim condition where some impact loading is expected.
Values for the QT300 condition
Other 4Cr13 tempers and conditions
4Cr13 is listed in 6 conditions; see the grade overview at 4Cr13.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft annealed bar, plate and sheet | Standard stocked delivery condition for machining, blanking and subsequent hardening. | 380 | 700 | 22 | 217 HB | — |
Cold drawn | Choose for close-tolerance shafting and screw-machine parts that will not be hardened. | 600 | 790 | 12 | 245 HB | — |
Q&T 600–680 °C | Toughest condition — for shafts, pump/valve stems and fasteners needing strength plus impact resistance rather than wear resistance. | 800 | 1,000 | 15 | 31 HRC | — |
QT300This page Q&T 300 °C | Slightly tougher mould / valve-trim condition where some impact loading is expected. | 1,350 | 1,650 | 6 | 49 HRC | — |
Q&T 200 °C | Standard cutlery / shear-blade / bearing condition — maximum wear resistance with minimum toughness loss. | 1,450 | 1,750 | 4 | 52 HRC | — |
Hardened | Maximum as-quenched hardness; brittle and must normally be tempered before service. | — | 1,950 | 1 | 56 HRC | — |
What is 4Cr13-QT300?
4Cr13-QT300 is 4Cr13 heat treated to QT300 — slightly tougher mould / valve-trim condition where some impact loading is expected. 4Cr13-QT300 has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,650 MPa (239 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 200 GPa (29 Msi). 4Cr13-QT300 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,425°C (2,597 °F). Annealed is the default condition FabDigit quotes; QT300 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 90/100, better than 100% of stainless steel grades
- High strength — 1,350 MPa (196 ksi), better than 99% of stainless steel grades
- High electrical conductivity — 3.1 % IACS, better than 99% of stainless steel grades
- Conducts heat well — 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades
- Low embodied carbon — 3.6 kg CO₂/kg, better than 83% of stainless steel grades
Limitations
- Limited ductility — 6%, worse than 99% of stainless steel grades
- Low fracture toughness — 25 MPa·√m (22.8 ksi·√in), worse than 99% of stainless steel grades
- Limited service temperature — 250°C (482 °F), worse than 99% of stainless steel grades
- Difficult to machine — 18/100, worse than 99% of stainless steel grades
- Difficult to weld — 30/100, worse than 88% of stainless steel grades
4Cr13-QT300 properties
Typical room-temperature values for 4Cr13-QT300; 16 are specific to this condition. Other listed values are 4Cr13 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
4Cr13-QT300 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
4Cr13-QT300 has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,650 MPa (239 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
4Cr13-QT300 is rated for continuous service to 250°C (482 °F). It conducts heat at 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades. Thermal expansion is 10.3 µm/m·K (5.72 µin/in·°F).
Electrical3
4Cr13-QT300 conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 80% of stainless steel grades.
Sustainability4
Producing a kilogram of 4Cr13-QT300 takes about 46 MJ of energy and emits 3.6 kg of CO₂ — less than 88% of stainless steel grades. Typical recycled content is 55%.
Manufacturability6
4Cr13-QT300's machinability is poor (18/100, worse than 99% of stainless steel grades); weldability poor (30/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4Cr13-QT300
Is 4Cr13 easy to machine?
Machine in the annealed state with sharp, rigid tooling, low speeds and flood coolant; hardened >45 HRC parts need carbide/CBN or grinding and EDM.
Can 4Cr13 be welded?
Poor weldability — preheat 200–300 °C, use matching or austenitic (309/310) filler and temper immediately after welding to avoid HAZ cracking.
Can 4Cr13 be formed, bent or molded?
Only light cold forming in the annealed condition (bending radii ≥2t); hot work at 1100–850 °C and always slow-cool or anneal after hot forging.
What surface finishes work on 4Cr13?
Takes an excellent mirror polish (mould cavities); passivate in nitric or citric acid after grinding/polishing, and hard chrome or nitriding can be added for extra wear life.
4Cr13 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 |
|---|---|---|
| CGB/T 1220 40Cr13 | 0.36 – 0.45 | 0.4 |
| Si | ≤ 0.6 | 0.35 |
| Mn | ≤ 0.8 | 0.45 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cr | 12 – 14 | 13 |
| Niresidual | ≤ 0.6 | — |
| Fe | balance | — |
4Cr13-QT300 — frequently asked
What is 4Cr13-QT300 used for?
4Cr13-QT300 is typically used for cutting tools, medical instruments and bearing rings. In short: harder than 3Cr13; mirror-polishing mould grade; low-cost cutlery stainless.
What is the yield strength of 4Cr13-QT300?
4Cr13-QT300 has a typical yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,650 MPa (239 ksi) — stronger than 99% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 4Cr13-QT300 easy to machine?
Not especially — machinability is rated poor (18/100, worse than 99% of stainless steel grades). Machine in the annealed state with sharp, rigid tooling, low speeds and flood coolant; hardened >45 HRC parts need carbide/CBN or grinding and EDM.
Can 4Cr13-QT300 be welded?
Not readily — weldability is rated poor (30/100). Poor weldability — preheat 200–300 °C, use matching or austenitic (309/310) filler and temper immediately after welding to avoid HAZ cracking.
What surface finishes work on 4Cr13-QT300?
Takes an excellent mirror polish (mould cavities); passivate in nitric or citric acid after grinding/polishing, and hard chrome or nitriding can be added for extra wear life.
Can 4Cr13-QT300 be formed, bent or molded?
Only light cold forming in the annealed condition (bending radii ≥2t); hot work at 1100–850 °C and always slow-cool or anneal after hot forging.
What is the maximum service temperature of 4Cr13-QT300?
4Cr13-QT300 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4Cr13 Annealed and 4Cr13-QT200?
Annealed is the default condition — standard stocked delivery condition for machining, blanking and subsequent hardening. QT200: standard cutlery / shear-blade / bearing condition — maximum wear resistance with minimum toughness loss. Yield strength is 380 MPa in Annealed versus 1,450 MPa in QT200.
Sources
- GB/T 1220 (40Cr13/4Cr13) — SAC (2007)
- ASTM A276/A276M Stainless Steel Bars and Shapes (Type 420, UNS S42000) — ASTM (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- Type 420 Stainless Steel product data sheet — AK Steel / Cleveland-Cliffs (2018)
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.