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Steel G26CrMo4 +A (Annealed)

Heat-treated state

EN 1.7221

Pick for maximum machinability and stress-free rough machining before final quench and temper.

Standard cost $$

Values for the +A 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 datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
+AThis page
Annealed
Pick for maximum machinability and stress-free rough machining before final quench and temper.30052022155 HB—
Normalized
Pick for thick, geometrically awkward castings where quench distortion or cracking is a risk and mid-range strength suffices.32055020170 HB—
+QT1Default
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.34057020175 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.4906801520 HRC—

What is G26CrMo4 +A?

G26CrMo4 +A is G26CrMo4 heat treated to +A — pick for maximum machinability and stress-free rough machining before final quench and temper. G26CrMo4 +A has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 86% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi). G26CrMo4 +A 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). +QT1 is the default condition FabDigit quotes; +A is available on request or by drawing note.

Advantages

  • Easy to machine — 65/100, better than 93% of steel grades
  • High service temperature — 450°C (842 °F), better than 86% of steel grades

Limitations

  • Low strength — 300 MPa (43.5 ksi), worse than 86% of steel grades
  • Limited formability — 20/100, worse than 80% of steel grades

G26CrMo4 +A properties

Typical room-temperature values for G26CrMo4 +A; 11 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 +A 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).

Density7.85 g/cm³0.28 lb/in³
Melting Point (Solidus)1,425°C2,597 °F
Liquidus Temperature1,505°C2,741 °F

Mechanical16

G26CrMo4 +A has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 86% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).

Elastic (Young's) Modulus210 GPa30.5 Msi
Shear Modulus80 GPa11.6 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)520 MPa75.4 ksi
Yield Strength (0.2% offset)300 MPa43.5 ksi
Elongation at Break22%
Reduction in Area45%
Compressive Strength340 MPa49.3 ksi
Shear Strength400 MPa58 ksi
Fatigue Strength (Endurance Limit)225 MPa32.6 ksi
Fracture Toughness (K_IC)90 MPa·√m81.9 ksi·√in
Charpy V-Notch Impact (RT)45 J33.2 ft·lbf
Hardness, Brinell155 HB
Hardness, Rockwell B82 HRB
Hardness, Vickers185 HV

Thermal6

G26CrMo4 +A is rated for continuous service to 450°C (842 °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).

Thermal Conductivity42 W/m·K24.3 BTU/hr·ft·°F
Specific Heat Capacity460 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)12.3 µm/m·K6.8 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)450°C842 °F
Min Service Temperature-30°C-22 °F

Electrical3

G26CrMo4 +A conducts electricity at 7.5 % IACS, worse than 67% of steel grades.

Electrical Conductivity7.5 % IACS
Electrical Resistivity2.3×10⁻⁷ Ω·m9.06 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.

Galvanic Potential (seawater, vs SCE)-0.6 V
Corrosion ResistanceNot recommended12/100
Chemical Resistance SummaryRusts freely in moist air and water; needs paint, zinc/phosphate or plating. Fine in dry oils, fuels and neutral hydrocarbons; attacked by acids, chlorides and wet H2S (HIC/SSC risk unless hardness capped ≤22 HRC).

Sustainability4

Producing a kilogram of G26CrMo4 +A takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 80%.

Embodied Energy (primary production)27 MJ/kg11,608 BTU/lb
Embodied Carbon (primary production)2.1 kg CO₂/kg
Embodied Water55 L/kg6.6 gal/lb
Typical Recycled Content80%

Manufacturability7

G26CrMo4 +A's machinability is good (65/100, better than 93% of steel grades); weldability good (60/100); formability poor (20/100).

MachinabilityGood65/100
Machinability Rating (AISI 1212 = 100 %)70%
WeldabilityGood60/100
Formability (cold)Poor20/100
CastabilityGood65/100
Brazeability / SolderabilityGood60/100
PolishabilityGood55/100

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with G26CrMo4 +A

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.

ElementSpec limit (wt %)Nominal
C0.22 – 0.290.26
Si≤ 0.60.4
Mn0.5 – 10.75
P0.025 max in some product standards≤ 0.020.02
S≤ 0.020.01
Cr0.8 – 1.21
Mo0.15 – 0.30.22
Niresidual≤ 0.4—
Curesidual≤ 0.3—
Vresidual≤ 0.05—
Febalance—

G26CrMo4 +A — frequently asked

What is G26CrMo4 +A used for?

G26CrMo4 +A 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 +A?

G26CrMo4 +A has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 86% of steel grades. Strength varies by condition: see the 4 listed tempers.

Is G26CrMo4 +A easy to machine?

Reasonably — machinability is rated good (65/100, better than 93% 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 +A be welded?

Yes — weldability is rated good (60/100). 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 +A?

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 +A 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 +A?

G26CrMo4 +A 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.

Sources

  1. EN 10293 — Steel castings for general engineering uses — CEN (2015)
  2. EN 10213 — Steel castings for pressure purposes — CEN (2016)
  3. ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
  4. Steel Castings Handbook, 6th ed. — SFSA / ASM International (1995)
  5. 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.