Steel G26CrMo4 +QT1
Heat-treated state · default condition
EN 1.7221
+QT1 = quenched and tempered, lower strength / higher toughness class
Default stock condition: balanced 500–650 MPa strength with high Charpy energy for pressure-retaining and general machinery castings.
Values for the +QT1 condition
Other G26CrMo4 tempers and conditions
G26CrMo4 is listed in 4 conditions; see the grade overview at G26CrMo4.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for maximum machinability and stress-free rough machining before final quench and temper. | 300 | 520 | 22 | 155 HB | — |
Normalized | Pick for thick, geometrically awkward castings where quench distortion or cracking is a risk and mid-range strength suffices. | 320 | 550 | 20 | 170 HB | — |
+QT1DefaultThis page Quenched and tempered, lower strength / higher toughness class | Default stock condition: balanced 500–650 MPa strength with high Charpy energy for pressure-retaining and general machinery castings. | 340 | 570 | 20 | 175 HB | — |
Quenched and tempered, higher strength class | Pick when higher yield strength (≈450 MPa class) is needed for gear housings, links and highly loaded machinery castings, accepting lower ductility and toughness. | 490 | 680 | 15 | 20 HRC | — |
What is G26CrMo4 +QT1?
G26CrMo4 +QT1 is G26CrMo4 heat treated to +QT1 — default stock condition: balanced 500–650 MPa strength with high Charpy energy for pressure-retaining and general machinery castings. G26CrMo4 +QT1 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 76% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi). G26CrMo4 +QT1 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Advantages
- High service temperature — 480°C (896 °F), better than 88% of steel grades
Limitations
- Limited formability — 20/100, worse than 80% of steel grades
- Low strength — 340 MPa (49.3 ksi), worse than 76% of steel grades
G26CrMo4 +QT1 properties
Typical room-temperature values for G26CrMo4 +QT1; 17 are specific to this condition. Other listed values are G26CrMo4 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
G26CrMo4 +QT1 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
G26CrMo4 +QT1 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 76% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
G26CrMo4 +QT1 is rated for continuous service to 480°C (896 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
G26CrMo4 +QT1 conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of G26CrMo4 +QT1 takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 80%.
Manufacturability7
G26CrMo4 +QT1's machinability is good (58/100, better than 75% of steel grades); weldability good (55/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with G26CrMo4 +QT1
Is G26CrMo4 easy to machine?
Machine in the annealed or +QT1 condition with carbide tooling at moderate speed and heavy feed; +QT2 at 215+ HB needs rigid setups and coolant to avoid work-hardened skins on cast surfaces.
Can G26CrMo4 be welded?
Weldable with low-hydrogen electrodes or GTAW/GMAW; preheat 200–250 °C, keep interpass temperature and apply 620–680 °C PWHT, then re-temper the casting after major repairs.
Can G26CrMo4 be formed, bent or molded?
Sand or investment cast; requires generous risers and chills because of the low-alloy shrinkage (~2 %), plus a full normalize or austenitize cycle to break up as-cast dendritic structure.
What surface finishes work on G26CrMo4?
No native corrosion barrier — shot blast then paint, zinc-rich primer, phosphate or hard chrome/nitride the wear faces; polishes reasonably but subsurface porosity can open up.
G26CrMo4 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 |
|---|---|---|
| C | 0.22 – 0.29 | 0.26 |
| Si | ≤ 0.6 | 0.4 |
| Mn | 0.5 – 1 | 0.75 |
| P0.025 max in some product standards | ≤ 0.02 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| Cr | 0.8 – 1.2 | 1 |
| Mo | 0.15 – 0.3 | 0.22 |
| Niresidual | ≤ 0.4 | — |
| Curesidual | ≤ 0.3 | — |
| Vresidual | ≤ 0.05 | — |
| Fe | balance | — |
G26CrMo4 +QT1 — frequently asked
What is G26CrMo4 +QT1 used for?
G26CrMo4 +QT1 is typically used for machinery housings, pressure part castings and general engineering components. In short: cast 4130-family steel; most weldable cast CrMo; medium-strength pressure castings.
What is the yield strength of G26CrMo4 +QT1?
G26CrMo4 +QT1 has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 76% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is G26CrMo4 +QT1 easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machine in the annealed or +QT1 condition with carbide tooling at moderate speed and heavy feed; +QT2 at 215+ HB needs rigid setups and coolant to avoid work-hardened skins on cast surfaces.
Can G26CrMo4 +QT1 be welded?
Yes — weldability is rated good (55/100). Weldable with low-hydrogen electrodes or GTAW/GMAW; preheat 200–250 °C, keep interpass temperature and apply 620–680 °C PWHT, then re-temper the casting after major repairs.
What surface finishes work on G26CrMo4 +QT1?
No native corrosion barrier — shot blast then paint, zinc-rich primer, phosphate or hard chrome/nitride the wear faces; polishes reasonably but subsurface porosity can open up.
Can G26CrMo4 +QT1 be formed, bent or molded?
Sand or investment cast; requires generous risers and chills because of the low-alloy shrinkage (~2 %), plus a full normalize or austenitize cycle to break up as-cast dendritic structure.
What is the maximum service temperature of G26CrMo4 +QT1?
G26CrMo4 +QT1 is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10293 — Steel castings for general engineering uses — CEN (2015)
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook, 6th ed. — SFSA / ASM International (1995)
- Stahlschlüssel / Key to Steel — material 1.7221 — Verlag Stahlschlüssel Wegst (2023)
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.