Steel G25NiCrMo6
EN 1.6554
G25NiCrMo6 (1.6554) is a quenched-and-tempered nickel-chromium-molybdenum cast alloy steel, supplied in the +QT1, +QT2, +N and +A conditions.
Reference datasheet — G25NiCrMo6 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 +QT1 condition
G25NiCrMo6 tempers and conditions
G25NiCrMo6 is supplied in 4 conditions, soft to hard. +QT1 is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Used for rough machining, extensive weld fabrication or repair before final quench and temper. | 400 | 640 | 18 | 11 HRC | 7.6 % IACS |
Normalized | Interim / lower-cost condition for lightly loaded or thick castings that will be machined and later hardened; strength well below +QT levels. | 480 | 720 | 15 | 18 HRC | 7.4 % IACS |
+QT1Default Quenched and tempered, lower strength class | Standard supply condition: best strength/toughness balance for heavy structural and machinery castings, easier to machine and weld-repair than +QT2. | 640 | 860 | 13 | 25 HRC | — |
Quenched and tempered, higher strength class | Choose when higher yield strength is needed for weight-critical highly loaded castings; accept lower ductility, toughness and machinability. | 750 | 960 | 10 | 30 HRC | — |
What is G25NiCrMo6?
G25NiCrMo6 (1.6554) is a quenched-and-tempered nickel-chromium-molybdenum cast alloy steel, supplied in the +QT1, +QT2, +N and +A conditions. It is chosen where a cast shape must carry shock and fatigue loading: the default condition gives 640 MPa yield, 860 MPa tensile, 13 % elongation and 255 HB (25 HRC), with service to 400 °C. The alloy has no inherent corrosion resistance and only moderate weldability (score 40), requiring 200–300 °C preheat and post-weld tempering; where the extra strength is not needed, the lower-alloyed G25NiCrMo3 is the simpler substitute. G25NiCrMo6 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F). G25NiCrMo6 has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 79% of steel grades. Elongation at break is 13% and the elastic modulus is 208 GPa (30.2 Msi).
What is G25NiCrMo6 used for?
- heavy machinery castings
- crankcases
- large structural components subject to shock loading
Advantages
- High strength — 640 MPa (92.8 ksi), better than 79% of steel grades
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
G25NiCrMo6 properties
Typical room-temperature values for G25NiCrMo6-+QT1; bars are the position among steel grades.
Physical3
G25NiCrMo6 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
G25NiCrMo6 has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 79% of steel grades. Elongation at break is 13% and the elastic modulus is 208 GPa (30.2 Msi).
Thermal6
G25NiCrMo6 is rated for continuous service to 400°C (752 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
G25NiCrMo6 conducts electricity at 7.2 % IACS, worse than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of G25NiCrMo6 takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 80%.
Manufacturability8
G25NiCrMo6's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (40/100); formability not recommended (10/100).
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 steel family
Yield strength against density for every steel grade FabDigit runs. G25NiCrMo6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with G25NiCrMo6
Is G25NiCrMo6 easy to machine?
Machine in +A/+N condition where possible; in +QT use rigid setups, carbide inserts at 60–120 m/min with positive feed and copious coolant, expect abrasive casting skin on first cut.
Can G25NiCrMo6 be welded?
Weldable with low-hydrogen matched Ni-Cr-Mo consumables; preheat 200–300 °C depending on section, maintain interpass temperature and apply post-weld tempering 30–50 °C below the last tempering temperature.
Can G25NiCrMo6 be formed, bent or molded?
Sand or no-bake moulded with generous risers and chills; keep section transitions gradual, allow ~2 % solidification shrinkage and normalize/homogenize before quench and temper.
G25NiCrMo6 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 |
|---|---|---|
| Clow enough for weld repair with preheat | 0.2 – 0.3 | 0.25 |
| Si | ≤ 0.6 | 0.4 |
| Mn | 0.5 – 0.9 | 0.7 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Cr | 0.4 – 0.9 | 0.65 |
| Nimain difference vs G25NiCrMo3 | 1.2 – 1.8 | 1.5 |
| Mohardenability, temper embrittlement resistance | 0.2 – 0.4 | 0.3 |
| Vresidual | ≤ 0.08 | |
| Fe | balance |
What surface finishes work on G25NiCrMo6?
Shot-blast to SA 2½, then epoxy/zinc-rich primer, hot-dip galvanizing or metallizing; can be nitrided or induction hardened locally for wear faces, chrome/nickel plating requires hydrogen bake-out.
Surface treatments FabDigit runs on 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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel G25NiCrMo6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.6554
How much does G25NiCrMo6 cost?
G25NiCrMo6 is a standard-cost 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.
G25NiCrMo6 — frequently asked
What is G25NiCrMo6 used for?
G25NiCrMo6 is typically used for heavy machinery castings, crankcases and large structural components subject to shock loading. In short: tougher than G25NiCrMo3; shock-load cast steel; weldable with preheat.
What is the yield strength of G25NiCrMo6?
G25NiCrMo6 has a typical yield strength of 640 MPa (92.8 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 79% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is G25NiCrMo6 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in +A/+N condition where possible; in +QT use rigid setups, carbide inserts at 60–120 m/min with positive feed and copious coolant, expect abrasive casting skin on first cut.
Can G25NiCrMo6 be welded?
With care — weldability is rated fair (40/100). Weldable with low-hydrogen matched Ni-Cr-Mo consumables; preheat 200–300 °C depending on section, maintain interpass temperature and apply post-weld tempering 30–50 °C below the last tempering temperature.
What surface finishes work on G25NiCrMo6?
Shot-blast to SA 2½, then epoxy/zinc-rich primer, hot-dip galvanizing or metallizing; can be nitrided or induction hardened locally for wear faces, chrome/nickel plating requires hydrogen bake-out.
Can G25NiCrMo6 be formed, bent or molded?
Sand or no-bake moulded with generous risers and chills; keep section transitions gradual, allow ~2 % solidification shrinkage and normalize/homogenize before quench and temper.
What is the maximum service temperature of G25NiCrMo6?
G25NiCrMo6 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.
How much does G25NiCrMo6 cost?
G25NiCrMo6 is a standard-cost 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 10293 — Steel castings for general engineering uses — CEN (2015)
- EN 10340 — Steel castings for structural uses — CEN (2007)
- EN 10027-2 — Numerical designation system for steels (material number 1.6554) — CEN (2015)
- ASM Handbook Vol.1: Properties and Selection — Cast Low-Alloy Steels — ASM International (1990)
- ASM Handbook Vol.15: Casting — ASM International (2008)
- Steel Castings Handbook — Steel Founders' Society of America / ASM (1995)
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.